154 results on '"Mahmoud Korek"'
Search Results
2. Electronic Structures and Transition Properties of BeSe and BeTe Molecules
- Author
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Israa Zeid, Nayla El-Kork, Mohamed Farjallah, Hela Ladjimi, Hamid Berriche, and Mahmoud Korek
- Subjects
Chemistry ,QD1-999 - Published
- 2021
- Full Text
- View/download PDF
3. Electronic Structure with Rovibrational Calculations of the Magnesium Monohalides MgX and Their Cations MgX+ (X = Cl, Br, and I)
- Author
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Nariman Abu el kher, Nayla El-Kork, and Mahmoud Korek
- Subjects
Chemistry ,QD1-999 - Published
- 2019
- Full Text
- View/download PDF
4. Electronic Structure Calculations with the Spin Orbit Effect of the Low-Lying Electronic States of the YbBr Molecule
- Author
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Wael Chmaisani, Nayla El-Kork, Soumaya Elmoussaoui, and Mahmoud Korek
- Subjects
Chemistry ,QD1-999 - Published
- 2019
- Full Text
- View/download PDF
5. Electronic Structure with Dipole Moment and Rovibrational Calculation of Cadmium Chalcogenide Molecules CdX (X = Se, Te)
- Author
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Khalil Badreddine and Mahmoud Korek
- Subjects
Chemistry ,QD1-999 - Published
- 2019
- Full Text
- View/download PDF
6. Laser cooling and electronic structure studies of CaK and its ions CaK±
- Author
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Amal Moussa, Nayla El-Kork, and Mahmoud Korek
- Subjects
laser cooling ,Franck–Condon factor ,dipole moment ,potential energy curves ,spectroscopic constants ,electronic structure ,Science ,Physics ,QC1-999 - Abstract
Aiming at a laser cooling investigation, we have used ab initio complete active space self consistent field (CASSCF)/(MRCI +Q) calculations to study the electronic structure of the diatomic molecule CaK and its molecular ions CaK ^+ and CaK ^− . The potential energy curves and the static dipole moment curves have been investigated for the considered molecules along with the spectroscopic constants T _e , ω _e , B _e , and R _e , in addition to the values of dipole moment μ _e and dissociation energy D _e . Overall, 19 and 14 electronic states have been studied respectively for CaK, CaK ^+ , from which 12 for CaK and six for CaK ^+ have been investigated here for the first time. Our obtained results agree well with data related to states that have been previously examined. Nineteen electronic states have been explored for CaK ^− , which up to our knowledge have not been previously calculated. The transition dipole moments have been calculated for the lowest Σ ^+ –Σ ^+ and Σ ^+ –Π transitions along with the Franck–Condon factor, Einstein coefficient, the spontaneous radiative lifetime, and the emission oscillator strength corresponding to the investigated transitions. A ro-vibrational analysis has been done via the canonical function approach, where the vibrational parameters E _v , B _v , D _v, and the turning points R _min and R _max have been determined. These calculations showed that the molecule CaK is a suitable candidate for Doppler laser cooling, and we propose a laser cooling scheme to this end. The Doppler limit temperature T _D and recoil temperature T _r have values as low as T _D = 51 μ K and T _r = 156 nK. The results should provide a useful reference for experimental spectroscopic and ultra-cold molecular physics studies.
- Published
- 2021
- Full Text
- View/download PDF
7. Theoretical electronic structure of the cadmium monohalide molecules CdX (X = F, Cl, Br, I)
- Author
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Khalil Badreddine and Mahmoud Korek
- Subjects
Physics ,QC1-999 - Abstract
The potential energy and dipole moment curves for the lowest electronic states in the representation 2s+1Λ(±) of CdX (X = F, Cl, Br, I) molecules are investigated via complete active space self-consistent field (CASSCF) and multi-reference configuration interaction MRCI (single and double excitation with Davidson correction). For the bound states of CdX diatomic molecules the bond distances Re, the vibrational harmonic frequencies ωe, the rotational constants Be, the electronic energies relative to the ground state Te, and the permanent and transition dipole moments have been computed. The dissociation energy limits of the atomic levels of CdX compounds are also calculated. The transition dipole moment between the ground state X2Σ+ and (2)2Σ+ is investigated. Consequently, the transition dipole moment values of the upper state at its equilibrium position μ21, the emission angular frequency ω21, the Einstein coefficients of spontaneous and induced emissions (A21 and B21ω), the spontaneous radiative lifetime τspon, the emission cross section σ0, the line strength and the emission oscillator strength f21 are calculated along with the ionicity of the X2Σ+ and (2)2Σ+ states. The eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constants Dv and the abscissas of the turning points Rmin and Rmax of X2Σ+ states of the CdX diatomics are computed. The comparison of the results with those available in literature shows a very good agreement.
- Published
- 2017
- Full Text
- View/download PDF
8. Extensive theoretical studies of the highly excited electronic states with the experimental parameters calculation for the laser cooling of CaI molecule
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Sahar Kassem, Israa Zeid, and Mahmoud Korek
- Subjects
General Physics and Astronomy - Abstract
By using the multireference configuration interaction method followed by Davidson correction, the electronic structure of the molecule CaI has been investigated. The potential energy curves, the permanent and transition dipole moment curves, and the spectroscopic parameters of 18 electronic states are investigated for these states, along with 111 vibrational levels of the four lowest electronic states. The Franck–Condon factors and the radiative lifetime are calculated for the X2Σ+–(1)2Π transition. For this transition, the vibrational branching ratio, the slowing distance L, and the number of cycles ( N) for photon absorption/emission are calculated along with the Doppler and the recoil temperatures. A pre-cooling temperature in a helium buffer gas is studied and a laser cooling scheme is presented. The calculation of these different experimental parameters is crucial to exploring the optimal conditions under which the laser cooling experiment of CaI molecule will be performed.
- Published
- 2023
9. Theoretical studies of the excited electronic states of the molecule ScLi and its ions ScLi± with a feasibility study of laser cooling
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Sahar Kassem, Israa Zeid, and Mahmoud Korek
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Organic Chemistry ,General Chemistry ,Catalysis - Abstract
For the transition metal lithides ScLi and ScLi±, the adiabatic potential energy and the static and transition dipole moment curves of the low-lying electronic states in the representation 2 s+1Λ(+/−) have been investigated. The spectroscopic constants, the electronic transition energy with respect to the ground state Te, the internuclear distance Re, the harmonic frequency ωe, the rotational constant Be, the permanent dipole moment µe, and the dissociation energies De have been computed for the bound and excited states. Using the canonical function approach, these calculations have been followed by a rovibrational calculation from which the rovibrational constants Ev, Bv, and Dv and the abscissas of the turning points Rmin and Rmax for the investigated bound states are calculated. A feasibility study of laser cooling of ScLi and its ions ScLi± has been done. New 62 electronic states have been investigated in the present work for the first time. No useful cooling scheme was found for those molecules.
- Published
- 2023
10. Molecular electronic structure of nanodiatomic metal oxide.
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Mahmoud Korek, Hana Abdel Nabi, and Nayla El-Kork
- Published
- 2013
- Full Text
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11. Laser cooling and electronic structure of Be halide anions BeX
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Amal, Madi, Nayla, El-Kork, Israa, Zeid, and Mahmoud, Korek
- Abstract
The adiabatic potential energy curves of the low lying electronic states of the Be halide anions BeX
- Published
- 2022
12. The effectiveness of the DIBH technique in protecting the heart of radiotherapy breast cancer patients treated at the American University of Beirut Medical Center in Lebanon
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Mahmoud Korek, Ahmad Maarouf, Youssef Zeidan, Ibrahim Duhaini, Bilal Shahine, and Abbas Mkanna
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medicine.medical_specialty ,Supine position ,business.industry ,medicine.medical_treatment ,Respiratory motion ,Biomedical Engineering ,Cancer ,Bioengineering ,medicine.disease ,Applied Microbiology and Biotechnology ,Radiation therapy ,Breast cancer ,medicine ,Radiology ,Breast disease ,Radiotherapy breast ,business ,Biotechnology ,Deep inspiration breath-hold - Abstract
While radiation therapy has been shown to increase local control and overall survival for breast cancer, cardiac toxicity remains a concern. Morbidity and mortality have been shown to increase proportionally to the mean heart dose. Deep inspiration breath hold (DIBH) can reduce heart dose compared to free-breathing (FB) delivery by increasing the distance from the heart to the chest wall, especially in left sided breast cancer. DIBH requires monitoring of patients’ respiratory motion. The purpose of this dosimetric study was to verify that DIBH planning technique can serve as an optimized technique concerning PTV coverage and better sparing of concerned OAR's. Retrospective analysis of 103 left-sided breast cancer patients who was treated using FB and DIBH with body surface tracking system. All of them were immobilized in the supine position. Treatment plans were created on FB and DIBH images to compare doses to the heart. Paired T-test was used to compare means and mean differences in heart. A comparison of DIBH and FB plans showed a decrease in mean and heart doses in all patients. Individual patients’ mean heart doses decreased by an average of 0.97 Gy, and the average mean heart dose for DIBH plans was significantly lower than for FB plans (0.74 vs 1.71 Gy; P
- Published
- 2021
13. Dosimetry comparison and evaluation of 3D and IMRT for left breast cancer radiotherapy techniques treated at ain wazein medical village hospital in Lebanon
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Ahmad Maarouf, Youssef Zeidan, Mahmoud Korek, Bilal Shahine, and Ibrahim Duhaini
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020205 medical informatics ,Equivalent dose ,business.industry ,medicine.medical_treatment ,Biomedical Engineering ,Cancer ,Bioengineering ,Retrospective cohort study ,02 engineering and technology ,medicine.disease ,Applied Microbiology and Biotechnology ,Radiation therapy ,03 medical and health sciences ,Left breast ,0302 clinical medicine ,Breast cancer ,0202 electrical engineering, electronic engineering, information engineering ,medicine ,Dosimetry ,030212 general & internal medicine ,Radiation treatment planning ,Nuclear medicine ,business ,Biotechnology - Abstract
Breast cancer patients undergoing radiation therapy can be treated using the 3D conformal or VMAT techniques. For both plans, the doses received by the target and the organs at risk are determined and compared with protocols recommended for the safety of the patients. CT simulations of 10 women with left breast cancer were used for a 3D conformal and VMAT treatment plans in the radiotherapy department of Ain Wazein Medical Village Hospital (AWMV) utilizing Monaco Treatment Planning system using Collapsed-cone and Monte Carlo algorithms respectively. The total prescribed dose to the PTV was 50 Gy in 25 fractions each 2 Gy. The dosimetric parameters obtained were mean, D95%, and homogeneity index for PTV; mean dose and max doses for the heart; the V20% for the left and the right lungs. All values of this retrospective study were analysed and compared to the normal tissue maximum dose tolerance. VMAT plans resulted in significantly better coverage for the target volume concepts as compared with 3D-CRT (D95: 97% vs. 82%, p-value = 0.002; Dmean 4953 cGy in 3D-CRT vs. 5093 cGy in VMAT, p-value = 0.01). The left lung (V20:28.44% with 3D-CRT vs. 21.93 with VMAT, p-value = 0.02). For the heart (Dmax = 4919 cGy in 3D-CRT vs. 4617 cGy in VMAT, p-value = 0.07). For the right lung (V20 was 0.12% in 3D-CRT vs. 0.52% in VMAT with p-value = 0.008). Even though the p-value was significant for the 3D conformal technique, the dose for both techniques was very low and non-significant to have a risk in the organ. The VMAT technique with correct target volume delineation allowed a significant dose escalation and an increase in Tumor Control Probability (TCP). VMAT resulted in an improved sparing of OARs as compared with 3D-CRT at equivalent dose levels.
- Published
- 2021
14. A theoretical electronic structure with a feasibility study of laser cooling of LaNa molecules with a spin orbit effect
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Israa Zeid, Nayla El-Kork, Wael Chmaisani, and Mahmoud Korek
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General Physics and Astronomy ,Physical and Theoretical Chemistry - Abstract
We investigate the electronic structure of the molecule LaNa in Λ and Ω representations. The transition (1)0+–(2)0+ seem suitable for the laser cooling of this molecule. Two lasers are sufficient; however additional pumping lasers can be used, if needed.
- Published
- 2022
15. Laser Cooling with an Intermediate State and Electronic Structure Studies of the Molecules CaCs and CaNa
- Author
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Amal Moussa, Nayla El-Kork, Israa Zeid, Ehab Salem, and Mahmoud Korek
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General Chemical Engineering ,General Chemistry - Abstract
The ground and excited electronic states of the diatomic molecules CaCs and CaNa have been investigated by implementing the ab initio CASSCF/(MRCI + Q) calculation. The potential energy curves of the doublet and quartet electronic low energy states in the representation
- Published
- 2022
16. Ab initio calculations of the XI molecules (X = Li, Na, K, Rb) with the ionicity and laser cooling analysis
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Israa Zeid, Mahmoud Korek, Rania Al Abdallah, and Nayla El-Kork
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chemistry.chemical_classification ,Physics ,Iodide ,Ab initio ,General Physics and Astronomy ,02 engineering and technology ,Electronic structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Potential energy ,Molecular physics ,0104 chemical sciences ,Dipole ,chemistry ,Ab initio quantum chemistry methods ,Laser cooling ,0210 nano-technology ,Adiabatic process - Abstract
For the alkali iodide molecules LiI, NaI, KI, and RbI, ab initio CASSCF/(MRCI+Q) calculations have been employed to investigate the adiabatic potential energy curves and the static dipole moment curves of the low-lying singlet and triplet electronic states in the representation 2S+1Λ(+/−). The spectroscopic constants Te, Re, ωe, Be, αe, the dipole moment μe, and the dissociation energies De have been computed for the bound states. Additionally, the percentage ionic character fionic around the equilibrium position of the ground state and the (2)1Σ+ state has been estimated. Using the canonical function approach, these calculations have been followed by a rovibrational calculation from which the rovibrational constants Ev, Bv, Dv, and the abscissas of the turning points Rmin and Rmax for the investigated bound states are calculated.
- Published
- 2020
17. Electronic Structures and Transition Properties of BeSe and BeTe Molecules
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Mahmoud Korek, Israa Zeid, Mohamed Farjallah, Hamid Berriche, Hela Ladjimi, and Nayla El-Kork
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Physics ,General Chemical Engineering ,Ab initio ,Ionic bonding ,General Chemistry ,Electronic structure ,Bond-dissociation energy ,Potential energy ,Article ,Chemistry ,Dipole ,Radiative transfer ,Molecule ,Atomic physics ,Physics::Chemical Physics ,QD1-999 - Abstract
The electronic structure of BeSe and BeTe molecules has been investigated using the ab initio CASSCF/(MRCI + Q) method at the spin-free and spin-orbit level. The potential energy curves, the permanent dipole moment, the spectroscopic constants Te, Re, ωe, and Be, and the dissociation energy De are determined in addition to the vertical transition energy Tv. The molecules' percentages of ionic character are deduced, and the trends of the spectroscopic constants of the two molecules are compared and justified. A ro-vibrational study is performed using the canonical function approach to calculate the constants Ev, Bv, and Dv and the turning points Rmin and Rmax. All the ground-state vibrational levels have also been investigated. The radiative lifetimes of vibrational transitions among the electronic ground states are also discussed. The results for BeSe have been compared with the previously published data while those for BeTe molecules are presented here for the first time.
- Published
- 2021
18. PIXE contribution for a database of Phoenician pottery in Lebanon
- Author
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Mahmoud Korek, Malek Tabbal, A. Srour, I. Oggiano, M. Castiglione, Bilal Nsouli, M. Roumié, A. Reslan, and Z. El-Morr
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Cultural influence ,Nuclear and High Energy Physics ,Elemental composition ,Database ,ion beam analysis ,02 engineering and technology ,021001 nanoscience & nanotechnology ,computer.software_genre ,language.human_language ,Eastern mediterranean ,Geography ,Iron Age ,0202 electrical engineering, electronic engineering, information engineering ,language ,020201 artificial intelligence & image processing ,Archaeological pottery ,Pottery ,Phoenician ,Multivariate statistical ,0210 nano-technology ,Instrumentation ,computer ,Phoenician pottery - Abstract
The study the ancient Phoenician cult place of Kharayeb, in the rural hinterland of Tyre, southern of Lebanon, dated to the Iron Age and Hellenistic periods is particularly helpful in evaluating the complexity and variability of the so called “Hellenism” and of “Greek cultural influences” in the Phoenician world. The PIXE analytical technique was used to characterize the elemental composition of several artefacts from this archaeological site, mainly figurines and some artisanal objects, with an attempt to analyze geological samples that could be potential clay sources in the area. Furthermore, the PIXE information about the composition of the studied objects helped to understand if the figurines were locally produced or imported from the coast and how was the process of production connected to the sanctuary. Hence, particle induced X-ray emission technique PIXE was used to determine the elemental composition of about 57 excavated fragments of figurines and pottery from Kharayeb site, as well as from two another archaeological sites, Jemjim and Tyre which is the prestigious city of antiquity, located on the eastern Mediterranean coast. Then, PIXE analyses with multivariate statistical methods were used to compare and to reveal characteristic groups. Finally, PIXE technique contributed to establish a first database of chemical composition of Phoenician pottery, which will broaden the existing database currently related only to archaeological pottery from coastal sites in Lebanon. Therefore, this work will probably be used for any future archaeological study on Phoenician pottery in the Phoenician colonies in the Mediterranean basin.
- Published
- 2019
19. Electronic structure with dipole moment and rovibrational calculations of the MgLi and MgNa molecules
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Mahmoud Korek, Dunia Houalla, Wael Chmaisani, and Sahar Kassem
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Physics ,010304 chemical physics ,General Physics and Astronomy ,Electronic structure ,Rotational–vibrational spectroscopy ,010402 general chemistry ,01 natural sciences ,Potential energy ,0104 chemical sciences ,Dipole ,Einstein coefficients ,0103 physical sciences ,Moment (physics) ,Molecule ,Atomic physics ,Adiabatic process - Abstract
We investigate an orderly study of the adiabatic potential energy curves for 29 and 30 low-lying 2s+1Λ+/− electronic states of the molecules MgLi and MgNa, respectively. The calculation has been done by using the complete active space self-consistent field followed by multi-reference configuration interaction with Davidson correction. For the investigated electronic states, the static and transition dipole moment curves are calculated along with the Einstein coefficients, the emission oscillator strength, the spontaneous radiative lifetime, the line strength, the classical radiative decay rate of the single-electron oscillator, the spectroscopic constants (Te, ωe, ωexe, Be, Re), and the equilibrium dissociation energy De. By means of the canonical functions approach, the ro-vibrational constants Ev, Bv, Dv, and the abscissas of the turning points, Rmin and Rmax, have been calculated for the considered electronic states up to the vibrational level v = 79. The Franck–Condon factors have been calculated and plotted for the transition between the low-lying electronic states of the two considered molecules. A good agreement is revealed between our calculated values and those available in the literature. Fifty new electronic states are investigated in the present work for the first time.
- Published
- 2019
20. Comparison of PET imaging with a 68Ga-labelled PSMA ligand versus 18F-choline PET/CT for the diagnosis of Prostate Cancer & Radioprotection for involved personnel
- Author
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Zeinab Khansa, Nemer Neaimeh, Mohamad Haidar, and Mahmoud Korek
- Subjects
PET-CT ,medicine.diagnostic_test ,Equivalent dose ,business.industry ,Biomedical Engineering ,Bioengineering ,Pet imaging ,Ligand (biochemistry) ,medicine.disease ,Applied Microbiology and Biotechnology ,Prostate cancer ,medicine.anatomical_structure ,Positron emission tomography ,medicine ,Abdomen ,Radiation protection ,Nuclear medicine ,business ,Biotechnology - Abstract
To compare the radiation dose delivered by Positron Emission Tomography (PET) due to Gallium-68 (68Ga) and Fluorine-18(18F) performed for patients with prostate cancer. The greatest importance is to understand how the extremely strong sources in use can be managed effectively and doses to persons and unwanted doses to patients can be minimized. Thus, Radiation safety measurements are necessary to achieve the lowest exposure with reasonable cost and effort. We prospectively analyzed studies from 70 patients who underwent PET-CT using 68Ga or 18F for diagnosis of prostate cancer between January 2017 and December 2017 at the American University of Beirut Medical Center. The dose rates were measured during the uptake period at patient body surface (abdomen) and at 1 m distance; these two points were measured after one hour of radionuclide uptake with background of 0.018 μSv. Then, the equivalent dose is calculated. Patients were selected consecutively until 70 cases were selected for each type of radionuclide. Data on 140 patients are presented. The maximum dose given to 68Ga PSMA (prostate-specific membrane antigen) patients was 5.80 mCi while doses to 18F-Choline patients reached 8.87 mCi. Cronbach’s Alpha values for the correlation between the masses and the dose rates was 0.530.Thus there is a small positive relationship between the body masses and the dose rates. This relationship is not statistically significant. Furthermore, the equivalent dose for both radionuclides was constant whatever the mass of the patient is. There is no effect of the body mass with respect to the dose rate, and equivalent dose due to both radionuclides 68Ga and 18F, which coincides with the principles of radiation protection. This leads to the suggestion that PET/CT equivalent doses with 68Ga-labelled PSMA ligand or 18F-Choline are similar and safe in the diagnosis of prostate cancer. However, 68Ga PSMA coincides more with radiation protection principles since the maximum equivalent dose due to 68Ga after 1 h at 1 m was 17.71 μSv while the maximum equivalent dose due to 18F after 1 h at 1 m was 39.51 μSv.
- Published
- 2019
21. Electronic Structure with Dipole Moment and Rovibrational Calculation of Cadmium Chalcogenide Molecules CdX (X = Se, Te)
- Author
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Mahmoud Korek and Khalil Badreddine
- Subjects
Physics ,General Chemical Engineering ,Transition dipole moment ,Multireference configuration interaction ,General Chemistry ,Electronic structure ,Rotational–vibrational spectroscopy ,Article ,lcsh:Chemistry ,Dipole ,lcsh:QD1-999 ,Einstein coefficients ,Ab initio quantum chemistry methods ,Complete active space ,Atomic physics - Abstract
Ab initio calculations of 51 electronic states in the representation 2s+1Λ(±) of CdX (X = Se, Te) molecules have been carried out by using the complete active space self-consistent field and multireference configuration interaction (single and double excitations with the Davidson correction). The potential energy along with the static and transition dipole moment curves for the investigated electronic states of the CdX molecules has been mapped. Consequently, the spectroscopic constants Re, ωe, Be, and Te have been computed for the bound states. The spectroscopic dissociation energy De, the zero-point energy, and the ionicity are also calculated for the bound electronic states X3Π, (1)1Σ+, (1)1Π, and (1)3Σ+. Rovibrational calculation is performed for the X3Π, (1)1Σ+, (1)1Π, and (1)3Σ+ states of CdSe together with the X3Π, (1)1Σ+, and (1)1Π states of a CdTe molecule. The Einstein coefficients of spontaneous and induced emissions, A21 and B21, are computed for the transition between the electronic states (1)3Σ+ and X3Π. In the present work, the values are well-consistent with those available in the literature.
- Published
- 2019
22. Electronic structure with the calculation of the rovibrational, and dipole moments of the electronic states of the NaBr and KBr molecules
- Author
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Israa Zeid, Mahmoud Korek, and Nayla El-Kork
- Subjects
050101 languages & linguistics ,Chemistry ,05 social sciences ,Transition dipole moment ,Ab initio ,General Physics and Astronomy ,02 engineering and technology ,Rotational–vibrational spectroscopy ,Electronic structure ,Potential energy ,Diatomic molecule ,Dipole ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,0501 psychology and cognitive sciences ,Singlet state ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Atomic physics - Abstract
Due to the lack of the electronic structure of NaBr and KBr diatomic molecules, a systematic investigation of the electronic structure of these molecules was performed using ab initio CASSCF/(MRCI + Q) calculations. The adiabatic potential energy curves of the low-lying singlet and triplet electronic states in the representation 2s+1Ʌ(+/−) of NaBr and KBr molecules have been investigated. The spectroscopic constants Te, Re, ωe, Be, α e , the dipole moment µe, and the dissociation energies De were calculated for the bound states in addition to the percentage ionic character fionic around the equilibrium position of two electronic states. Moreover, the static and the transition dipole moment curves have been calculated. The nuclear motion study has been performed using the canonical functions approach that allowed the determination of various rovibrational constants Ev, Bv, Dv and the abscissas of the turning points Rmin and Rmax for the investigated bound states. The investigated data are in a very good agreement with those given in literature. These results provide effective routes for many industrial applications and for the formation of cold alkali halide molecules in the low-lying vibrational states via experimental techniques.
- Published
- 2019
23. Laser cooling and electronic structure studies of BaI molecule
- Author
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Mahmoud korek, Israa Zeid, Nayla El-Kork, and Ali Mostafa
- Subjects
Physical and Theoretical Chemistry ,Condensed Matter Physics ,Biochemistry - Published
- 2022
24. Can SUVmax of 68Ga-labeled PSMA Ligand and 18F-choline PET/CT Be Used to Predict the Radiation Dose in Prostate Cancer Patients?
- Author
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Mahmoud Korek, Zeinab Khansa, Nemer Neaimeh, and Mohamad Haidar
- Subjects
Male ,Fluorine Radioisotopes ,Epidemiology ,Health, Toxicology and Mutagenesis ,Standardized uptake value ,Gallium Radioisotopes ,18F-choline ,Kidney ,Ligands ,Radiation Dosage ,030218 nuclear medicine & medical imaging ,Choline ,03 medical and health sciences ,Prostate cancer ,0302 clinical medicine ,Radiation Protection ,Positron Emission Tomography Computed Tomography ,Diagnostic Reference Levels ,Medicine ,Humans ,Radiology, Nuclear Medicine and imaging ,Prospective Studies ,Prospective cohort study ,Gallium Isotopes ,PET-CT ,Equivalent dose ,business.industry ,Radiation dose ,Prostatic Neoplasms ,Radionuclide uptake ,medicine.disease ,Therapeutic Equivalency ,030220 oncology & carcinogenesis ,Radiopharmaceuticals ,business ,Nuclear medicine - Abstract
Gallium-68 (Ga)-PSMA and F-Choline are two radionuclides that have already shown high potential for the detection of prostate cancer. The comparison between these two radionuclides has several advantages in radiation protection. The aim of this prospective study was to identify which of these two radionuclides can help in predicting the equivalent dose using the maximum standard uptake value (SUVmax) of normal organs, the kidneys. Two groups of 40 patients (total n = 80) who underwent PET/CT using Ga or F for diagnosis of prostate cancer between April 2018 and December 2018 at the American University of Beirut Medical Center were included. First, the dose rates were measured after 1 h of radionuclide uptake at 1 m distance with background of 0.015 μSv h. Then, SUVmax for kidneys were determined from images obtained with PET/CT 1 h after injection of both radionuclides. The ratios of the equivalent doses to the SUVmax for kidneys were compared for both Ga-PSMA and F-Choline. There is a positive moderate relationship between the SUVmax for kidneys and the Ga dose rate after 1 h of injection at 1 m distance from the abdomen (p-value = 0.0230.05). This relationship is statistically significant. However, there is a very low negative relationship between the SUVmax kidney and F dose rate after 1 h of injection at 1 m distance from the abdomen (p-value = 0.930.05). This relationship is not statistically significant. This leads to the suggestion that we can predict the equivalent dose due to Ga by indicating the SUVmax from the PET/CT images.
- Published
- 2020
25. Theoretical electronic structure with rovibrational studies of the molecules YP, YP+ and YP
- Author
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Mahmoud Korek, Nayla El-Kork, Ghina Chamieh, and Lokman Awad
- Subjects
Davidson correction ,Chemistry ,Ab initio ,Rotational–vibrational spectroscopy ,Electronic structure ,Configuration interaction ,Atomic and Molecular Physics, and Optics ,Analytical Chemistry ,Dipole ,Complete active space ,Physics::Chemical Physics ,Perturbation theory ,Atomic physics ,Instrumentation ,Spectroscopy - Abstract
Due to the absence of the electronic structure of the YP molecule and its ions in literature, this work is conducted via an ab initio Complete Active Space Self Consistent Field and the Multi-Reference Configuration Interaction with Davidson correction calculation (CASSCF/MRCI + Q) to investigate the low–lying electronic states of these molecules. Adiabatic potential energy curves (PECs) along with static dipole moment (DM) curves for 27, 24, and 21 low-lying electronic states in the representation of 2s+1Λ(+/−) for YP, YP+, and YP- molecules have been investigated, respectively. For the low-lying electronic states of the YP molecule and their anion and cation, the spectroscopic constants Re, Te, ωe, ωexe, Be, De are provided. The rovibrational constants Ev, Bv, Dv, and the abscissa of turning points Rmin and Rmax (up to vibrational level v = 37) are calculated using the canonical functions approach and referring to the calculated data from the PECs. Perturbation theory method is also used to compare our data's validity, as no results are presented in the literature for these molecules.
- Published
- 2022
26. Ab initio study of the low-lying electronic states of YbCl molecule including spin-obit effects
- Author
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Mahmoud Korek and Wael Chmaisani
- Subjects
Physics ,Radiation ,Davidson correction ,010304 chemical physics ,Ab initio ,01 natural sciences ,Quantum chemistry ,Atomic and Molecular Physics, and Optics ,Dipole ,Atomic electron transition ,0103 physical sciences ,Bound state ,Atomic physics ,010306 general physics ,Spin (physics) ,Ground state ,Spectroscopy - Abstract
Ab initio quantum chemistry calculations for the low-lying electronic states of YbCl molecule, including the spin-orbit effects, have been performed via the CASSCF/MRCI (single and double excitations with Davidson correction) method. Adiabatic potential energy curves have been investigated for the low-lying electronic states in the 2s+1Λ(+/−) and Ω representations. Static dipole moment curves of the most investigated states are also computed. The spectroscopic constants and the percentage ionic character fionic of the lowest doublet and quartet bound states are calculated. The transition dipole moments, the spontaneous radiative lifetime and some emission coefficients are determined for the lowest electronic transitions. By using the canonical functions approach, the ro-vibrational parameters are also determined for different bound states. New theoretical data is studied in this work. The Franck–Condon factors (FCFs) for transitions involving the low vibrational levels of the (2)1/2, (1)3/2 and (3)1/2 states are highly diagonally distributed, unlike the other investigated electronic transitions. The off-diagonal FCFs of the transitions between the lowest-excited states and the ground state, indicate that direct laser cooling of the studied molecule is experimentally difficult.
- Published
- 2018
27. Organ at risk dose measurements following radiotherapy treatment for breast cancer patients
- Author
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Saad Ayoubi, Mahmoud Korek, Ibrahim Duhaini, Ahmad Maarouf, Nour Hodroj, and Fatimah Farhat
- Subjects
medicine.medical_specialty ,Lung ,business.industry ,medicine.medical_treatment ,Biomedical Engineering ,Dose profile ,Bioengineering ,medicine.disease ,Applied Microbiology and Biotechnology ,Effective dose (radiation) ,030218 nuclear medicine & medical imaging ,Radiation therapy ,03 medical and health sciences ,0302 clinical medicine ,Breast cancer ,medicine.anatomical_structure ,030220 oncology & carcinogenesis ,medicine ,Dosimetry ,Radiology ,Lung cancer ,Radiation treatment planning ,business ,Biotechnology - Abstract
Radiotherapy technologies are one of the most common treatments for cancer, they have been successfully used to damage cancer cells, with as little harm as possible to nearby healthy cells, however Secondary cancer risk following radiotherapy is an increasingly important topic in clinical oncology with impact on treatment decision making and on patient management. The objective of this study is to measure the skin radiation dose received by the treated breast as well as the dose to the lungs in cancer patients undergoing breast radiotherapy and estimate the probability for radiation-induced cancer, i.e. secondary cancer and the probability of lung cancer. Usage of RANDO phantoms and GafChromic dosimetry films to do dose measurements during breast radiotherapy. Measured dose and calculated organ dose from patients were compared. The calculated doses were done using the effective dose formula. Measured point doses of both lungs were compared to those calculated by TPS (treatment planning system). Relative Risk (RR) and Probability of Causation (PC) of lungs- probability of cancer- were calculated from patient’s mean doses to the organs (right lung and left lung) using the model described in BEIR V report. RR mean values were 1.278 and 1.032 for ipsilateral and contralateral lungs respectively. In addition, PC mean values were 20.93 % and 3.099% for ipsilateral and contralateral lungs respectively. Breast cancer patients are susceptible to an increased risk of secondary cancer of ipsilateral lungs more than in the contralateral ones.
- Published
- 2018
28. Electronic structure of the BaO molecule with dipole moments and ro-vibrational calculations
- Author
-
Mohamed Khatib and Mahmoud Korek
- Subjects
Davidson correction ,Oscillator strength ,Chemistry ,Transition dipole moment ,02 engineering and technology ,Electronic structure ,Configuration interaction ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Analytical Chemistry ,Dipole ,Einstein coefficients ,Rotational spectroscopy ,Atomic physics ,0210 nano-technology ,Instrumentation ,Spectroscopy - Abstract
The twenty-three low-lying electronic states (singlet and triplet) of the BaO molecule have been studied by using an ab initio method. These electronic states have been investigated by using the Complete Active Apace Self-Consistent Field (CASSCF) followed by multi-reference configuration interaction (MRCI+Q) with Davidson correction. The potential energy curves, the internuclear distance Re, the harmonic frequency ωe, the rotational constant Be, the electronic energy with respect to the ground state Te and the static and transition dipole moment have been investigated. The Einstein spontaneous and induced emission coefficients A21 and B21ω as well as the spontaneous radiative lifetime τspon, emission wavelength λ21 and oscillator strength f21 have been calculated by using the transition dipole moment between some doublet electronic states. The calculation of the eigenvalues Ev, the rotational constant Bv, the centrifugal distortion constant Dv, and the abscissas of the turning points Rmin and Rmax have been done by using the canonical functions approach. A very good agreement is shown by comparing the values of our work to those found in the literature for many electronic states. Eighteen new electronic states have been studied here for the first time.
- Published
- 2018
29. Theoretical electronic structure of the molecules SrX (X = Li, Na, K) toward laser cooling study
- Author
-
Israa Zeid, Sahar Kontar, Wael Chmaisani, Nayla El-Kork, Mahmoud Korek, and Tanya Atallah
- Subjects
Alkaline earth metal ,Chemistry ,Transition dipole moment ,Ab initio ,02 engineering and technology ,Electronic structure ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Alkali metal ,01 natural sciences ,Biochemistry ,Potential energy ,Laser cooling ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,Molecule ,Physics::Atomic Physics ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Atomic physics ,010306 general physics ,0210 nano-technology - Abstract
The potential energy curves of the low-lying electronic states of the SrX (X = Li, Na, K) molecules have been investigated by using the ab initio CASSCF/(MRCI + Q) calculation. For the considered electronic states the spectroscopic constants Te, ωe, Be, Re, αe, De the static and transition dipole moment curves, and the Franck-Condon factor (FCF) have been calculated. The study of the nuclear motion using the canonical functions approach allowed to determine different vibrational constants Ev, Bv, Dv and the turning points Rmin and Rmax up to the vibrational level v = 105. The comparison of the investigated data shows a very good agreement with those given in literature. These results have a great significance to experimentalists as they provide efficient routes to form cold alkali and alkaline earth molecules in low-lying vibrational states via experimental techniques.
- Published
- 2018
30. Theoretical electronic structure with dipole moment and rovibrational calculation of the low-lying electronic states of the HgF molecule
- Author
-
Wael Chmaisani, Mahmoud Korek, and Soumaya Elmoussaoui
- Subjects
Physics ,Radiation ,Oscillator strength ,Transition dipole moment ,02 engineering and technology ,Electronic structure ,Rotational–vibrational spectroscopy ,Configuration interaction ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Dipole ,Excited state ,Atomic physics ,0210 nano-technology ,Ground state ,Spectroscopy - Abstract
With the lack of evitable data about the electronic structure of the low-lying states of the HgF molecule unlike its counter parts of mercury monohalides, spectroscopic study of eighteen low-lying doublet and quartet electronic states in the representation 2s+1Λ(+\-) of this molecule is conducted. Adiabatic potential energy curves of those states are investigated using the complete active space self consistent field (CASSCF) calculation with multi-reference configuration interaction (MRCI) method including single and double excitations with Davidson correction (+Q). The spectroscopic constants as Re, ωe, ωexe, Be, αe, Te and μe are calculated for the bound states. The dissociation energy D 0 0 and the percentage ionic character fionic are also computed. The transition dipole moment μTDM between some doublet low-lying states is studied and some emission coefficients as the Einstein spontaneous coefficients A21, the spontaneous radiative lifetime τspon, and the oscillator strength f21 are thus determined. A rovibrational study has been done to investigate the vibrational levels of the low-lying bound states and the vibrational constants Ev, Bv, Dv, Rmin and Rmax are reported. The Franck–Condon factors have also been calculated for the most probable transitions between the excited states and the ground state. The comparison between the values of the present work and those short information available in the literature shows good accordance.
- Published
- 2017
31. Electronic structure of SrO molecules with dipole moments and ro-vibrational calculations
- Author
-
Mohamed Khatib and Mahmoud Korek
- Subjects
Physics ,010304 chemical physics ,Oscillator strength ,Transition dipole moment ,General Physics and Astronomy ,Electronic structure ,Configuration interaction ,01 natural sciences ,Dipole ,Einstein coefficients ,0103 physical sciences ,Rotational spectroscopy ,Atomic physics ,010306 general physics ,Ground state - Abstract
Ab initio calculations have been applied to investigate the electronic structure of the SrO molecule. The potential energy curves have been computed in the Born–Oppenheimer approximation for the ground, and the 29 low-lying singlet and triplet excited electronic states. Complete active space self-consistent field, multi-reference configuration interaction have been utilized to investigate these states. The harmonic frequency ωe, the internuclear distance Re, the rotational constant Be, and the electronic energy with respect to the ground state Te have been calculated by using two different techniques of calculation with different bases. The transition dipole moment between some doublet states is used to determine the Einstein spontaneous A21 and induced emission B 21 ω coefficients as well as the spontaneous radiative lifetime τspon, emission wavelength λ21 and oscillator strength f21. The eigenvalues Ev, the rotational constant Bv, the centrifugal distortion constant Dv, and the abscissas of the turning ...
- Published
- 2017
32. Electronic structure calculation of the MgAlk (Alk = K, Rb, Cs) molecules for laser cooling experiments
- Author
-
Mahmoud Korek, Dunia Houalla, Nayla El-Kork, and Wael Chmaisani
- Subjects
Chemistry ,Transition dipole moment ,Ab initio ,Ionic bonding ,02 engineering and technology ,Electronic structure ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,Alkali metal ,01 natural sciences ,Biochemistry ,Potential energy ,Laser cooling ,0103 physical sciences ,Molecule ,Physical and Theoretical Chemistry ,Atomic physics ,010306 general physics ,0210 nano-technology - Abstract
The potential energy curves for the molecules MgK, MgRb and MgCs have been computed by using the ab initio CASSCF/ (MRCI + Q) calculation. For the considered electronic states the static and transition dipole moment curves have been calculated along with the Franck-Condon factor (FCF), the spectroscopic constants T e , ω e , ω e x e , B e , R e , and the fraction of ionic character. By using the canonical functions approach, the ro-vibrational constants E v , B v , D v and the abscissas of the turning points R min , and R max , have been calculated. For these molecules, more than 109 electronic states have been investigated in the present work. These results have great significance to experimentalists as they provide efficient routes to form cold alkali and alkaline earth molecules.
- Published
- 2017
33. Electronic structure with rovibrational and dipole moment calculation of the diatomic molecules AsBr and AsI
- Author
-
S. N. Abdul-Al, Mahmoud Korek, and Khaled A. Mourad
- Subjects
010304 chemical physics ,010504 meteorology & atmospheric sciences ,Chemistry ,Transition dipole moment ,Electronic structure ,Rotational–vibrational spectroscopy ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Potential energy ,Diatomic molecule ,Dipole ,0103 physical sciences ,Rotational spectroscopy ,Physical and Theoretical Chemistry ,Atomic physics ,Ground state ,0105 earth and related environmental sciences - Abstract
CASSCF/MRCI calculations have been performed for the ground and the low-lying singlet and triplet excited electronic states, in the representation 2s+1Λ(+/−) of the diatomic molecules AsBr and AsI. Twenty and seventeen excited electronic states have been investigated respectively for AsBr AsI molecules. The potential energy curves, the electronic energy with respect to the ground state Te, the harmonic frequency ωe, the internuclear distance Re, the rotational constant Be, and the static and transition dipole moment have been investigated for the considered electronic states. The comparison between these constants of the four As-halides has been done along with the energy levels Te for the different electronic states. By using the canonical functions approach, the eigenvalue Ev, the rotational constant Bv, and the abscissas of the turning points Rmin and Rmax have been calculated for the considered electronic states up to the vibrational level v = 100. The comparison between the values of the present work with the experimental data available in the literature shows a very good agreement. This study represents the first theoretical investigation of the electronic structure of both AsBr and AsI molecules.
- Published
- 2017
34. Electronic structure with dipole moment and ionicity calculations of the low-lying electronic states of the ZnF molecule
- Author
-
Mahmoud Korek, Nayla El-Kork, and Soumaya Elmoussaoui
- Subjects
Davidson correction ,010304 chemical physics ,Oscillator strength ,Chemistry ,Organic Chemistry ,Transition dipole moment ,02 engineering and technology ,General Chemistry ,Configuration interaction ,021001 nanoscience & nanotechnology ,01 natural sciences ,Catalysis ,Molecular electronic transition ,Dipole ,0103 physical sciences ,Rotational spectroscopy ,Atomic physics ,0210 nano-technology ,Ground state - Abstract
Adiabatic potential energy curves of the 28 low-lying doublet and quartet electronic states in the representation 2s+1Λ(±) of the zinc monofluoride molecule are investigated using the complete active space self-consistent field (CASSCF) with multi-reference configuration interaction (MRCI) method including single and double excitations with the Davidson correction (+Q). The internuclear distance Re, the harmonic frequency ωe, the static and transition dipole moment μ, the rotational constant Be, and the electronic transition energy with respect to the ground state Te are calculated for the bound states. The transition dipole moment between some doublet states is used to determine the Einstein spontaneous A21 and induced emission [Formula: see text] coefficients, as well as the spontaneous radiative lifetime τspon, emission wavelength λ21, and oscillator strength f21. The ground state ionicity qionicity and equilibrium dissociation energy DE,e are also computed. The comparison between the values of the present work and those available in the literature for several electronic states shows very good agreement. Twenty-three new electronic states have been studied in the present work for the first time.
- Published
- 2017
35. Ab-initio calculations of the electronic structure of the alkaline earth hydride anions XH
- Author
-
Israa, Zeid, Rania, Al Abdallah, Nayla, El-Kork, and Mahmoud, Korek
- Abstract
By the use of the ab initio CASSCF/(MRCI+Q) calculations in the representation
- Published
- 2019
36. Electronic structure of the SrH+ and BaH+ molecules with dipole moment and rovibrational calculations
- Author
-
Mahmoud Korek, Nariman Abu el kher, Israa Zeid, and Nayla El-Kork
- Subjects
Physics ,General Computer Science ,Absorption spectroscopy ,Ab initio ,02 engineering and technology ,Rotational–vibrational spectroscopy ,01 natural sciences ,Diatomic molecule ,010305 fluids & plasmas ,Theoretical Computer Science ,Dipole ,Heteronuclear molecule ,Modeling and Simulation ,Excited state ,0103 physical sciences ,Physics::Atomic and Molecular Clusters ,0202 electrical engineering, electronic engineering, information engineering ,020201 artificial intelligence & image processing ,Physics::Atomic Physics ,Physics::Chemical Physics ,Atomic physics ,Spectroscopy ,Astrophysics::Galaxy Astrophysics - Abstract
The alkaline-earth metal hydrides and their corresponding ions are heteronuclear molecules that are essential in many fields especially in astrophysics and spectroscopy such as sunspots, stars, nebulae, the interstellar medium and chemical engineering. They are important systems in spectroscopy due to their visible bands which emerge in the absorption spectrum of sun. Due to the importance of hydride species and the lack of theoretical studies on some astronomical diatomic molecules is a main reason to investigate their electronic structure. The adiabatic potential energy curves and the static dipole moment curves of the low-lying electronic states of strontium hydride cation SrH+ and barium hydride cation BaH+ have been investigated using ab initio CASSCF/(MRCI + Q) calculations. The spectroscopic parameters Te, Re, ωe, Be, the dipole moment μe, and the dissociation energy De were calculated for the bound states. Using the canonical function approach, the rovibrational constants Ev, Bv, Dv and the turning points Rmin and Rmax for the ground and several excited states have been determined.
- Published
- 2021
37. Laser cooling and electronic structure studies of CaK and its ions CaK±
- Author
-
Nayla El-Kork, Mahmoud Korek, and Amal Moussa
- Subjects
Physics ,Laser cooling ,General Physics and Astronomy ,Electronic structure ,Atomic physics ,Ion - Abstract
Aiming at a laser cooling investigation, we have used ab initio complete active space self consistent field (CASSCF)/(MRCI +Q) calculations to study the electronic structure of the diatomic molecule CaK and its molecular ions CaK+ and CaK−. The potential energy curves and the static dipole moment curves have been investigated for the considered molecules along with the spectroscopic constants T e, ω e, B e, and R e, in addition to the values of dipole moment μ e and dissociation energy D e. Overall, 19 and 14 electronic states have been studied respectively for CaK, CaK+, from which 12 for CaK and six for CaK+ have been investigated here for the first time. Our obtained results agree well with data related to states that have been previously examined. Nineteen electronic states have been explored for CaK−, which up to our knowledge have not been previously calculated. The transition dipole moments have been calculated for the lowest Σ+–Σ+ and Σ+–Π transitions along with the Franck–Condon factor, Einstein coefficient, the spontaneous radiative lifetime, and the emission oscillator strength corresponding to the investigated transitions. A ro-vibrational analysis has been done via the canonical function approach, where the vibrational parameters E v, B v, D v, and the turning points R min and R max have been determined. These calculations showed that the molecule CaK is a suitable candidate for Doppler laser cooling, and we propose a laser cooling scheme to this end. The Doppler limit temperature T D and recoil temperature T r have values as low as T D = 51 μK and T r = 156 nK. The results should provide a useful reference for experimental spectroscopic and ultra-cold molecular physics studies.
- Published
- 2021
38. Electronic structure of the ZnCl molecule with rovibrational and ionicity studies of the ZnX (X=F, Cl, Br, I) compounds
- Author
-
Mahmoud Korek, Nayla El-Kork, and Soumaya Elmoussaoui
- Subjects
010504 meteorology & atmospheric sciences ,Chemistry ,Oscillator strength ,Transition dipole moment ,Rotational–vibrational spectroscopy ,Configuration interaction ,010402 general chemistry ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Molecular electronic transition ,0104 chemical sciences ,Einstein coefficients ,Rotational spectroscopy ,Physical and Theoretical Chemistry ,Atomic physics ,Ground state ,0105 earth and related environmental sciences - Abstract
Based on the complete active space self consistent field (CASSCF) method with multi-reference configuration interaction MRCI calculations including single and double excitations with Davidson correction (+Q), twenty three low lying electronic states in the 2s+1Λ(±) representation of the zinc monochloride ZnCl molecule are investigated considering 7 and 9 valence electrons. The internuclear distance Re, the harmonic frequency ωe, the permanent dipole moment μ, the rotational constant Be and the electronic transition energy with respect to the ground state Te are calculated for the bound states. The transition dipole moment between some doublet states is used to determine the Einstein spontaneous A 21 and induced emission B 21 ω coefficients, the spontaneous radiative lifetime τ spon , the emission wavelength λ 21 , the oscillator strength f 21 and the line strength S 21 . The fraction of the ground state ionic character f and equilibrium dissociation energy DE,e are also computed. Using the canonical function approach, the eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constants Dv and the abscissas of the turning points Rmin and Rmax of the zinc monohalide molecules ZnX (X: F, Cl, Br, I) are calculated. The comparison between the values of the present work and those available in the literature for several electronic states shows good accordance.
- Published
- 2016
39. Theoretical study with dipole moment calculation of new electronic states of the molecule BF
- Author
-
Ghassan Younes, Nayla El-Kork, Sally Al Shawa, and Mahmoud Korek
- Subjects
Bond dipole moment ,Technology ,potential energy curves ,Transition dipole moment ,Physical and theoretical chemistry ,QD450-801 ,Energy Engineering and Power Technology ,Medicine (miscellaneous) ,Electronic structure ,TP1-1185 ,010402 general chemistry ,01 natural sciences ,Electronic states ,dipole moments ,Biomaterials ,0103 physical sciences ,Molecule ,Physics::Chemical Physics ,Physics ,ab initio calculation ,010304 chemical physics ,Process Chemistry and Technology ,Chemical technology ,electronic structure ,0104 chemical sciences ,Surfaces, Coatings and Films ,Moment (mathematics) ,Dipole ,spectroscopic constants ,Atomic physics ,Biotechnology - Abstract
The potential energy curves for the 45 singlet, triplet, and quintet electronic states in the representation 2s+1Λ(+/-) of the BF molecule have been investigated using the complete active space self-consistent field (CASSCF) method with multireference configuration interaction (MRCI). The internuclear distance Re, the harmonic frequency ωe, the static dipole moment μ, the rotational constants Be, and the electronic transition energy with respect to the ground state Te have been calculated for the considered electronic states. The comparison between the values of the present work and those available in the literature for several electronic states shows a very good agreement. Twelve electronic states of BF molecule are reported here for the first time that are not yet observed experimentally.
- Published
- 2016
40. Electronic structure calculation of the KYb molecule with dipole moments, polarizabilities, and ro-vibrational studies
- Author
-
Samir N. Tohme and Mahmoud Korek
- Subjects
Field (physics) ,Chemistry ,02 engineering and technology ,Electronic structure ,Configuration interaction ,021001 nanoscience & nanotechnology ,Condensed Matter Physics ,01 natural sciences ,Biochemistry ,Potential energy ,Diatomic molecule ,Dipole ,Ab initio quantum chemistry methods ,Polarizability ,0103 physical sciences ,Physical and Theoretical Chemistry ,Atomic physics ,010306 general physics ,0210 nano-technology - Abstract
Ab initio calculations are used to provide the spectroscopic constants ( T e , D e , ω e , B e , and R e ) of the low-lying electronic states for the Potassium–Ytterbium (KYb) compound. The potential energy curves (PECs) have been obtained using the multi-configuration self-consistent field multi-reference configuration interaction (MCSCF/MRCI) calculations. Using the data of the computed PECs and by using the canonical functions approach, the ro-vibrational constants ( E v , B v , D v , R min , and R max ) have been calculated for the electronic states up to the vibrational level v = 86. The permanent and transition dipole moments along with the components of the electric dipole polarizability ( α ) have been also calculated. The KYb molecule is experimentally unknown, which provides the focus of the work introduced here by presenting the electronic structure of this new diatomic species. Differences of the previous studied molecules (Alkali–Yb compounds) by our research group are compared with the electronic structure of the current calculated compound. Twenty new molecular electronic states are reported here for the first time.
- Published
- 2016
41. Ab Initio Calculation of the Electronic States of ScTe Molecule below 19,500 cm-1
- Author
-
Rawad Halabi and Mahmoud Korek
- Subjects
Physics ,Davidson correction ,Ab initio ,02 engineering and technology ,Electronic structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Potential energy ,Molecular electronic transition ,0104 chemical sciences ,Dipole ,Rotational spectroscopy ,Atomic physics ,0210 nano-technology ,Ground state - Abstract
The potential energy curves (PECs) of the16 lowest electronic states in the representation 2s+1Λ (+/-) of the molecule ScTe have been investigated via ab initio CASSCF and MRCI (single and double excitations with Davidson correction) calculations. The permanent dipole moment curves (PDMCs) and the spectroscopic constants such as vibrational harmonic frequency ωe, the internuclear distance at equilibrium Re, the rotational constant Be, and the electronic transition energy Te with respect to the ground state have been calculated for the different bound investigated electronic states. The comparison of the present results with the rare available theoretical data in literature shows an overall good agreement. To the best of our knowledge, 15 electronic states of the ScTe molecule are not yet investigated either experimentally or theoretically, they are investigated in the present work for the first time.
- Published
- 2016
42. Theoretical calculation of the electronic states below 326 000 cm−1 of the NaHe molecule
- Author
-
S. Kontar and Mahmoud Korek
- Subjects
Physics ,General Physics and Astronomy ,Molecule ,Multireference configuration interaction ,Atomic physics ,Potential energy ,Electronic states - Abstract
The potential energy curves have been investigated for the lowest 54 electronic states in the [Formula: see text] representation of the molecule NaHe via the multireference configuration interaction method (MRCI) and second-order multireference perturbation theory (RPST2-RS2). The harmonic vibrational frequency, ωe, the internuclear distance, Re, the electronic energy with respect to the ground state, Te, and the permanent dipole moment, μ, have been calculated. The positions of Rmin and Rmax and their minimum and maximum energies Emin and Emax with respect to the dissociation asymptote have been determined for the considered electronic states. The comparison of our investigated values to the theoretical and experimental data available in the literature shows a good agreement. Forty-three electronic states have been studied theoretically in the present work for the first time.
- Published
- 2015
43. Theoretical study of the alkali hydride anions XH–(X = Li, Na, and K)
- Author
-
Nayla El-Kork, Mahmoud Korek, Sally Al Shawa, and Israa Zeid
- Subjects
010304 chemical physics ,Chemistry ,Transition dipole moment ,Ab initio ,General Physics and Astronomy ,Rotational–vibrational spectroscopy ,010402 general chemistry ,01 natural sciences ,Molecular physics ,Bond-dissociation energy ,0104 chemical sciences ,Dipole ,Excited state ,0103 physical sciences ,Bound state ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Ground state - Abstract
The electronic structure of the alkali hydride anions (LiH-, NaH-, and KH-), has been investigated via ab initio CASSCF/(MRCI + Q) and R-Matrix method calculations. Comparison between the results of the two calculation methods show that the pure bound state method may be unsuitable for the calculation of the electronic states of LiH- molecule, as the potential energy curves that it presents may be spurious. The adiabatic potential energy curves and the dipole moment curves of the low-lying electronic states of alkali hydride anionic molecules are investigated in the representation 2s+1Ʌ(+/-) where the percentage ionic character fionic around the equilibrium position of the ground state X2Σ+ has been calculated. Additionally, the spectroscopic constants Te, Re, ωe, Be, the dipole moment µe, and the dissociation energy De were computed for the bound states of the two molecules NaH- and KH-. The transition dipole moment curves for the lowest 2Σ+– 2Π transition have been also presented along with their Franck-Condon factor (FCF). A rovibrational study has been performed using the canonical functions approach in order to study the nuclear motion and find the rovibrational constants for the ground and several excited states. The diagonal Franck-Condon factor f00 may provide efficient routes for the formation of cold and ultracold molecules.
- Published
- 2020
44. Theoretical electronic structure with rovibrational calculations of alkali-beryllium molecules BeX (X = K, Rb, Cs)
- Author
-
Ghina Chamieh, Mahmoud Korek, and Lokman Awad
- Subjects
Physics ,chemistry ,Physical chemistry ,Molecule ,chemistry.chemical_element ,Rotational–vibrational spectroscopy ,Electronic structure ,Beryllium ,Condensed Matter Physics ,Alkali metal ,Potential energy ,Mathematical Physics ,Atomic and Molecular Physics, and Optics - Published
- 2020
45. Ab-initio calculations of the electronic structure of the alkaline earth hydride anions XH− (X = Mg, Ca, Sr and Ba) toward laser cooling experiment
- Author
-
Israa Zeid, Nayla El-Kork, Mahmoud Korek, and Rania Al Abdallah
- Subjects
Hydride ,Chemistry ,Transition dipole moment ,Ab initio ,02 engineering and technology ,Rotational–vibrational spectroscopy ,010402 general chemistry ,021001 nanoscience & nanotechnology ,01 natural sciences ,Bond-dissociation energy ,Atomic and Molecular Physics, and Optics ,0104 chemical sciences ,Analytical Chemistry ,Dipole ,Ab initio quantum chemistry methods ,Excited state ,Physics::Atomic and Molecular Clusters ,Physics::Atomic Physics ,Physics::Chemical Physics ,Atomic physics ,0210 nano-technology ,Instrumentation ,Spectroscopy - Abstract
By the use of the ab initio CASSCF/(MRCI+Q) calculations in the representation 2s+1Λ(+/−), the adiabatic potential energy curves and the dipole moment curves of the low lying states of the alkaline earth hydride anions (MgH−, CaH−, SrH− and BaH−) have been investigated in their singlet and triplet multiplicities. The spectroscopic parameters Te, Re, ωe, Be, αe, the dipole moment μe, and the dissociation energy De have been also calculated for the bound states of the considered molecules. In addition, a systematic investigation of the transition dipole moment curves for the lowest 1Σ+-1Π transitions has been done along with the Franck-Condon factor (FCF) corresponding to the X1Σ+-(1)1Π transition. Using the canonical function approach, a rovibrational study has been performed for finding the rovibrational constants Ev, Bv, Dv and the turning points Rmin and Rmax for the ground and different excited bound state. Efficient routes may be achieved via the diagonal FCF for the formation of cold and ultracold alkaline earth hydride anions. PACS No 31.10. + z, 31.15.A, 31.15.vn, 31.50.Df.
- Published
- 2020
46. Solution of the Rovibrational Schrödinger Equation of a Molecule Using the Volterra Integral Equation
- Author
-
Mahmoud Korek and Nayla El-Kork
- Subjects
Physics ,010304 chemical physics ,Article Subject ,Differential equation ,lcsh:QD450-801 ,lcsh:Physical and theoretical chemistry ,Rotational–vibrational spectroscopy ,Quantum number ,01 natural sciences ,Volterra integral equation ,Schrödinger equation ,symbols.namesake ,Quantum mechanics ,0103 physical sciences ,symbols ,Rotational spectroscopy ,Physical and Theoretical Chemistry ,Perturbation theory ,010306 general physics ,Wave function - Abstract
By using the Rayleigh-Schrödinger perturbation theory the rovibrational wave function is expanded in terms of the series of functions ϕ0,ϕ1,ϕ2,…ϕn, where ϕ0 is the pure vibrational wave function and ϕι are the rotational harmonics. By replacing the Schrödinger differential equation by the Volterra integral equation the two canonical functions α0 and β0 are well defined for a given potential function. These functions allow the determination of (i) the values of the functions ϕι at any points; (ii) the eigenvalues of the eigenvalue equations of the functions ϕ0,ϕ1,ϕ2,…ϕn which are, respectively, the vibrational energy Ev, the rotational constant Bv, and the large order centrifugal distortion constants Dv,Hv,Lv….. Based on these canonical functions and in the Born-Oppenheimer approximation these constants can be obtained with accurate estimates for the low and high excited electronic state and for any values of the vibrational and rotational quantum numbers v and J even near dissociation. As application, the calculations have been done for the potential energy curves: Morse, Lenard Jones, Reidberg-Klein-Rees (RKR), ab initio, Simon-Parr-Finlin, Kratzer, and Dunhum with a variable step for the empirical potentials. A program is available for these calculations free of charge with the corresponding author.
- Published
- 2018
- Full Text
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47. Electronic structure with vibration–rotation study of the NaYb molecule
- Author
-
Samir N. Tohme and Mahmoud Korek
- Subjects
Dipole ,Davidson correction ,Chemistry ,Distortion ,General Physics and Astronomy ,Molecule ,Electronic structure ,Physical and Theoretical Chemistry ,Atomic physics ,Rotation ,Potential energy ,Eigenvalues and eigenvectors - Abstract
The potential energy curves have been investigated for the 15 lowest doublet and quartet electronic states in the 2s+1Λ± representation of the molecule NaYb via CASSCF/MRCI (single and double excitations with Davidson correction) calculations. The spectroscopic constants (Te, De, ωe, Be, re, …) have been calculated in addition to the permanent dipole moments μ. By using the canonical functions approach, the eigenvalues Ev, the rotational constants Bv, the centrifugal distortion constant Dv, and the abscissas of the turning points rmin and rmax have been calculated for different electronic states. Fourteen molecular states have been studied theoretically for the first time.
- Published
- 2015
48. Electronic structure with dipole moment calculation of the low-lying electronic states of ZnBr molecule
- Author
-
Mahmoud Korek and Soumaya Elmoussaoui
- Subjects
Bond dipole moment ,Davidson correction ,Chemistry ,Transition dipole moment ,Multireference configuration interaction ,Condensed Matter Physics ,Biochemistry ,Molecular electronic transition ,Ab initio quantum chemistry methods ,Rotational spectroscopy ,Physics::Chemical Physics ,Physical and Theoretical Chemistry ,Atomic physics ,Ground state - Abstract
Adiabatic potential energy curves of 19 low-lying doublet and quartet electronic states in the representation 2s+1 Λ (±) of the zinc mono-bromide molecule ZnBr are investigated using high correlated ab initio calculations. For the bound states, the equilibrium internuclear distance R e , the harmonic frequency ω e , the rotational constant B e and the electronic transition energy with respect to the ground state T e have been calculated at the multireference configuration interaction (MRCI) level including single and double excitations with Davidson correction (+Q). Sixteen low-lying states are presented here for the first time. The ground state dissociation energy is also calculated. The comparison between the values of the present work are in agreement with those available in the literature.
- Published
- 2015
49. Electronic structure with dipole moment calculation of the low-lying electronic states of the molecule ZnI
- Author
-
Mahmoud Korek and Soumaya Elmoussaoui
- Subjects
Physics ,Dipole ,Radiation ,Davidson correction ,Electronic structure ,Complete active space ,Configuration interaction ,Perturbation theory ,Atomic physics ,Ground state ,Potential energy ,Spectroscopy ,Atomic and Molecular Physics, and Optics - Abstract
The potential energy curves of the low-lying 26 doublet and quartet electronic states in the representation 2 s +1 Λ (+/−) of the ZnI molecule have been investigated using the Complete Active Space Self Consistent Field (CASSCF) with Multi-Reference Configuration Interaction (single and double excitation with Davidson correction) MRCI+ Q method and the second order multi-reference Rayleigh Schrodinger perturbation theory RSPT2-RS2 method. The harmonic frequency ω e , the internuclear distance R e , the static dipole moment, and the electronic energy with respect to the ground state T e have been calculated for the considered bound electronic states. The comparison between the values of the present work and those available in the literature shows a good agreement. Twenty-three electronic states are studied here for the first time.
- Published
- 2015
50. Electronic Structure of the Cesium Oxide Molecule CsO
- Author
-
S. N. Abdul-Al, Diana Kaeen, and Mahmoud Korek
- Subjects
Physics ,Davidson correction ,Mechanical equilibrium ,law ,Ab initio ,Electronic structure ,Rotational spectroscopy ,Physics::Chemical Physics ,Atomic physics ,Adiabatic process ,Potential energy ,Molecular electronic transition ,law.invention - Abstract
Adiabatic potential energy curves of 12 doublet and quartet lowest spinless electronic states of the molecule CsO have been investigated via ab initio CASSCF and MRCI (doublet and quartet excitations with Davidson correction) calculations. The spectroscopic constants such as vibrational harmonic frequency ωe, the internuclear distance at equilibrium Re, the rotational constant Be, and the electronic transition energy Te of the ground and the excited electronic states have been calculated by fitting the energy values around the equilibrium position to a polynomial in terms of the internuclear distance. The comparison of these values to those available in the literature shows a good agreement.
- Published
- 2015
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