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Dermatological patients are a distinctive group of patients who experience social stigmatisation, exclusion, and a significant decrease in the quality of life. In the healthcare delivery setting, medical staff (especially nurses) are expected to ensure patients with skin diseases' comfort and bio-psycho-social well-being. Undoubtedly, the realisation of this goal is facilitated by the staff's dermatological knowledge of the causes of the disease and its impact on the patient and their quality of life. The study was based on the opinions of nurses not working in dermatology departments, focusing on their perception of patients with skin problems and selected issues related to their quality of life.

Purpose: To determine the level of physical activity in young and early adults with type 1 diabetes in comparison with their healthy counterparts and to determine whether the use of insulin pump facilitates physical activity. Materials and methods: This study included 40 type 1 diabetes (T1D) subjects of both sexes treated with a personal insulin pump therapy, and 30 healthy controls. The diagnostic survey included questions about nutrition, knowledge about the disease and whether the patient can control diabetes through physical activity, diet and self-monitoring. The International Physical Activity Questionnaire – long form (IPAQ-L), was used to assess the level of physical activity of both diabetic and control individuals. Results: 87.5% T1D subjects believe that using an insulin pump facilitates their physical activity. The level of physical activity associated with cycling (p=0.038) and vigorous physical activity (p=0.008) was higher in T1D than in the control group. Statistically significant differences (p=0.043) were found for total physical activity. The total mean activity was higher in participants with T1D (8147.70 MET-min/week) compared to the control group (5857.55 MET-min/week). Conclusions: Young and early adults with type 1 diabetes may be more physically active than their healthy counterparts, mainly in their leisure time. The use of a personal insulin pump facilitates physical activity, but most diabetics experience episodes of hypoglycemia after physical activity.

Vibrational corrections to geometry of cytosine were evaluated at several different levels of theory and for several basis sets. The effects of these corrections on bond lengths involving hydrogen atoms as well as bond and dihedral angles involving the amine group were found to be more significant than correlation and basis set effects. A comparison with the bond lengths of C–H and N–H bonds involving cytosine in double stranded DNA structures that were deposited in Nucleic Acid Database showed that the length of both types of bonds in vast majority of structures is underestimated. In addition, the influence of vibrational effects on the shielding constants of all atoms was analyzed. It was found that vibrational averaging lowered the values of shielding constants of all atoms. Particularly, large vibrational corrections were found for nitrogen and oxygen nuclei, but proton shielding was not found to be significantly affected. © 2010 Wiley Periodicals, Inc. Int J Quantum Chem, 2011

The combination of phototoxic drugs and ultraviolet (UV) radiation can trigger the release of proinflammatory cytokines. The present study measured the ability of sunscreens to prevent cytokine secretion in human keratinocytes following cotreatment of these cells with a known photoreactive drug and UVA. Keratinocytes were treated for 1 h with increasing concentrations of lomefloxacin (LOM) or norfloxacin (NOR), exposed to 15 J/cm2 UVA, and incubated for 24 h. NOR, owing to the absence of a fluorine atom in position 8, was non-phototoxic and used as a negative control. Cell viability and the release of 3 cytokines were assessed, namely interleukin-1α (IL-1α), interleukin-6 (IL-6), and tumour necrosis factor-α (TNF-α). The measurement of these cytokines may be a useful tool for detecting photoreactive compounds. To measure their ability to prevent cytokine secretion, various sunscreens were inserted between the UVA source and the cells. Treatment with NOR, NOR plus UVA, or LOM had no effect on the cells. LOM plus UVA, however, had an effect on cell viability and on cytokine secretion. IL-1α levels increased with LOM concentration. The release of TNF-α and IL-6 followed the same pattern at lower concentrations of LOM but peaked at 15 µmol/L and decreased at higher concentrations. Sunscreens protected the cells from the effects of LOM plus UVA, as cell viability and levels of cytokines remained the same as in the control cells. In conclusion, the application of broad-spectrum sunscreen by individuals exposed to UVA radiation may prevent phototoxic reactions initiated by drugs such as LOM.

A method is proposed for partitioning the supermolecule interaction energy obtained from density functional theory calculations. Exploratory calculations for Ar2 reveal serious shortcomings of several commonly used correlation functionals. There are also problems with exchange functionals resulting in unphysical behavior at long range. These findings clearly demonstrate the limitations of some commonly used functionals.

Ab initio calculations were performed with the coupled-cluster single and double excitations with perturbative triples correction method using the augmented correlation consistent polarized triple, quadruple, and quintuple zeta basis sets [aug-cc-pVnZ (n=T,Q,5)] for four complexes: He–Kr, Ne–Kr, Ar–Kr, Kr2. For each complex and each basis set a fitted potential energy curve is given. The most accurate results were obtained with the aug-cc-pV5Z basis set supplemented with an additional (3s3p2d2 f1g) set of bond functions. Ab initio potentials were compared to experimental data and the best empirical potentials available. The agreement was good although calculated potentials were found to be too shallow. To better reproduce spectroscopic data, ab initio potentials were modified using a nonlinear least-squares procedure. The modified potentials were developed for He–Kr, Ne–Kr, Ar–Kr, and Kr2, as well as Ne–Ar and Ar2. They all compare favorably with the best available empirical potentials.

The Na2B, Na3, and H3 trimers in the lowest quartet states were studied by ab initio methods, using both the supermolecular approach and the intermolecular Møller-Plesset perturbation theory. Partitioning of the nonadditive contribution into the orientational two-body part and the genuine three-body part was proposed. The lowest quartet state of the Na3 trimer and all the three lowest quartet states of the Na2B trimer are bound, and the forms of these clusters are essentially determined by two-body forces. In the case of the Na2B trimer the orientational two-body nonadditivity proved to be crucial. In addition, in the title metal trimers, in the region of the van der Waals minima, the genuine nonadditivity is very important, and amounts to 30% in Na2B and up to 70% in Na3. The leading nonadditive term is the triple-exchange Heitler-London exchange term. For triangular arrangements it considerably enhances the total stabilization. The single-exchange term and the SCF deformation play only a secondary role. The dispersion nonadditivity is negligible. The isotropic part of the basis set superposition error (BSSE) is large and must be corrected by the counterpoise method. The anisotropic contribution to BSSE is practically negligible.

According to the Early External Cephalic Version (EECV2) Trial, planning external cephalic version (ECV) early in pregnancy results in fewer breech presentations at delivery compared with delayed external cephalic version. A Cochrane review conducted after the EECV2 Trial identified an increase in preterm birth associated with early ECV. We examined whether a policy of routine early ECV (i.e., before 37 weeks' gestation) is more or less costly than a policy of delayed ECV.We undertook this analysis from the perspective of a third-party payer (Ministry of Health). We applied data, using resources reported in the EECV2 Trial, to the Canadian context using 10 hospital unit costs and 17 physician service/procedure unit costs. The data were derived from the provincial health insurance plan schedule of medical benefits in three Canadian provinces (Ontario, Alberta, and British Columbia). The difference in mean total costs between study groups was tested for each province separately.We found that planning early ECV results in higher costs than planning delayed ECV. The mean costs of all physician services/procedures and hospital units for planned ECV compared with delayed ECV were $7997.32 versus $7263.04 in Ontario (P0.001), $8162.82 versus $7410.55 in Alberta (P0.001), and $8178.92 versus $7417.04 in British Columbia (P0.001), respectively.From the perspective of overall cost, our analyses do not support a policy of routinely planning ECV before 37 weeks' gestation.

Cybulski M., Sierka E. (2015). Istotne zmiany w standardzie zarządzania środowiskowego ISO 14001, wersja 2015. In: Inżynieria Produkcji. Strona społeczna i przemysłowa (ed. Siwka J., Sierka E.), Częstochowa, 71-86.

Thirty-two nucleic acid hydrogen-bonded base pairs have been examined using second-order Miller-Plesset perturbation theory (MP2) and the 6-31G*(0.25) and modified aug-cc-pVDZ basis sets. Complexes of C s symmetry have been constructed from rigid monomers which allowed us to use a compact parametrization of their geometry based on the center of mass separation and Euler angles. The dependence of the interaction energy and its components on small geometrical modifications around the minima have been examined. The electrostatic and the exchange energies have been found to be the most important components of the overall interaction energy, although the dispersion and the induction energies also play important roles. The exchange energy, while typically not the largest in magnitude at the minima, is the most anisotropic component for rotations of the monomers in the plane of the complex. The analysis of the electron-correlated components reveals that the effect of the attractive dispersion energy is to a large degree canceled out by the repulsive correlation correction to the exchange energy.

Fourth-order Moller–Plesset perturbation theory (MP4) and perturbation theory of intermolecular forces were employed to investigate the potential energy surface of the NH 3 –CO complex. Most calculations were performed using a relatively large, well-tempered basis set, though for a few selected structures an augmented basis set with bond functions was used. The global minimum of −1489 μ E h was found for a bent hydrogen-bonded configuration at the intermolecular distance of 4.3 A. The minimum energy area was discovered to be very wide and flat making the complex extremely flexible. A model potential function for the complex was developed.

The nonadditive interactions in the Ar2H2O cluster, in a variety of geometries, are studied using the supermolecular Moller–Plesset (MP) perturbation theory in conjunction with the perturbation theory of intermolecular forces. The three-body effect is dissected into several components: the Heitler–London exchange, induction, dispersion, and second-order supermolecular MP perturbation nonadditivity. The latter term is further analyzed within the framework of pseudodimer treatment. The Heitler–London exchange is dissected into the SE (single exchange) and TE (triple exchange) parts. Analytical representations of the nonadditive terms are discussed. For the exchange (SE) and induction, the multicenter expansions work very well. However, in the case of the three-body dispersion term, the single-center dipole-dipole-dipole plus dipole-dipole-quadrupole expression proves to be more suitable. © 2002 Wiley Periodicals, Inc. Int J Quantum Chem, 2002

The CH3F···H2O complex has been studied using both the supermolecule approach through fourth-order Moller−Plesset perturbation theory (MP4) and perturbation theory of intermolecular forces. Nine co...

Potential energy surfaces for the X 2Π and A 2Σ+ states of the He⋅OH and Ne⋅OH complexes have been developed, using the restricted open-shell coupled cluster [RCCSD(T)] method. These potentials have been used to calculate rotation-vibration energies for both electronic states of these complexes and their deuterated analogs. Good agreement with the available experimental vibrational energies and rotational constants is obtained. In spite of being relatively weakly bound, the vibrational eigenstates for both electronic states of these species display significant deviations from the simple zero-order free-rotor/anharmonic oscillator limit, leading to potentially rich spectra. © 2000 American Institute of Physics.

The potential energy surface for the ground state of the Ar–NO−(3Σ−) complex has been calculated at the unrestricted Mo/ller–Plesset perturbation theory through the fourth order (UMP4). Calculations have been performed using the augmented correlation-consistent polarized triple zeta basis set supplemented with bond functions (aug-cc-pVTZ+bf ). The global minimum with a well depth of approximately 651 cm−1 has been found for an approximate T-shaped structure (R=6.28 ao and Θ=83.62°). Two other, local minima correspond to two collinear forms, Ar–N–O and N–O–Ar. All these minima are located in the regions of local reduction of exchange repulsion. The ground vibrational state dissociation energy D0 determined by the collocation method has been found to be 587 cm−1. Several rovibrational states have been predicted and characterized. The ground-state complex assumes a fairly rigid T-shaped structure. The trimer, Ar2NO−(3Σ−), is also of the T-shaped-cross structure, and the pairwise equilibrium and dissociation ...

A combined ab initio atoms-in-molecule approach was implemented to model the photoelectron spectra of the ArO− anion. The lowest adiabatic states of Σ and Π symmetry of ArO and ArO− were investigated using the fourth-order Moller–Plessett perturbation theory including bond functions. The total energies were dissected into electrostatic, exchange, induction, and dispersion components. The complex of Ar with atomic oxygen is only weakly bound, primarily by dispersion interaction. The Π state possesses a deeper minimum (Re=3.4 A,De=380 μEh) than the Σ state (Re=3.8 A,De=220 μEh). In contrast, the anion complex is fairly strongly bound, primarily by ion-induced dipole induction forces, and the Σ state possesses a deeper minimum at shorter interatomic distances (Re=3.02 A,De=3600 μEh) than the Π state (Re=3.35 A,De=2400 μEh). The Σ–Π splittings in both systems are mainly due to differences in the exchange repulsion terms. Atoms-in-molecule models were used to account for the spin–orbit interaction, and to gene...

Adiabatic potential energy surfaces for the 2A′ and 2A″ states of the Ar(1S)–OH(X2Π) complex were calculated using supermolecular unrestricted fourth-order Moller–Plesset perturbation theory and a large correlation consistent basis set supplemented with bond functions. The potential energy surface (PES) of the A′ state has two minima. The global minimum from the unrestricted coupled-cluster calculations with single, double, and noniterative triple excitations occurs for the collinear geometry Ar–H–O at R=7.08a0 with a well depth of De=141.2 cm−1. There is also a local minimum for the skewed T-shaped form, whereas the Ar–O–H arrangement corresponds to a saddle point. The PES of the A″ state also has two minima, which occur for the two collinear isomers. A variational calculation of the bound rovibrational states was performed. The calculated binding energy, D0=93.8 cm−1, and the energies of the bound vibrational states are in good agreement with experiment [see Berry et al., Chem. Phys. Lett. 178, 301 (199...

The two-dimensional potential energy surfaces for the Ar–CO complex have been developed using single and double excitation coupled-cluster theory with noniterative treatment of triple excitations [CCSD(T)]. The most accurate results have been obtained with the augmented correlation-consistent polarized triple zeta basis set (aug-cc-pVTZ) with an additional (3s3p2d2f1g) set of bond functions. The minimum of −104.68 cm−1 has been found at (R,Θ)=(3.714 A, 92.88°), where R and Θ denote the Jacobi coordinates with Θ=0° corresponding to the linear Ar–OC geometry and Θ=180° to the linear Ar–CO geometry. Dynamical calculations have been performed to determine the frequencies of various rotational and rovibrational transitions. The overall agreement with experiment is good. For example, the calculated frequencies of the intermolecular bending and stretching vibrations, 12.015 and 18.520 cm−1, respectively, agree very well with the experimental values (12.014 and 18.110 cm−1).

Potential energy curves for three homonuclear (He2, Ne2, Ar2) and three heteronuclear (He–Ne, He–Ar, Ne–Ar) rare gas dimers are presented. The curves were calculated using several correlation consistent basis sets and the supermolecule single and double excitation coupled-cluster theory with noniterative perturbational treatment of triple excitations, CCSD(T). The most accurate results were obtained with the aug-cc-pV5Z basis set supplemented with an additional (3s3p2d2f1g) set of bond functions. The results obtained with a smaller aug-cc-pVQZ+(3s3p2d2f1g) basis set are almost as accurate. Both basis sets give results in better agreement with potentials based on experiments than the recent results obtained with larger d-aug-cc-pV6Z and t-aug-cc-pV6Z basis sets but without bond functions. For each complex and each basis set a fitted potential energy curve is given. In addition, for each complex, with the exception of He2, the values of Re, De, B0, D0, and 〈R〉0 are given. For He2 no bound states were found ...

High quality ab initio calculations for the interaction of He with the B 3Π0u+ state of Cl2 for three r(Cl–Cl) distances, and for the He(1S)+Cl(2P) interaction are used to obtain a three-dimensional potential energy surface for the system. The surface was used to calculate HeCl2 excitation spectra, predissociation lifetimes, and product state distributions for comparison with experimental data, and yields a remarkably good agreement. The largest discrepancy is in the dependence of the lifetime on the excited state vibrational level. The calculated lifetimes are too short for the lowest measured vibrational levels. To investigate how the surface could be modified to obtain even better agreement, a microgenetic algorithm was used to adjust the potential parameters to improve the fit. The adjusted surface has a softer repulsive wall for small Cl–Cl separations which helps to lengthen the excited state lifetimes and yields better agreement with the data. Also, the shape of the well region is adjusted somewhat...

A new ab initio two-dimensional potential energy surface for the Ne–CO interaction is described. The surface was obtained by the supermolecule method at the CCSD(T) level of theory. It is compared with several experimental data sets and with the symmetry-adapted perturbation theory (SAPT) surface of Moszynski et al. [J. Phys. Chem. A 101, 4690 (1997)]. The new surface gives modestly better predictions of experimental results that depend on close approach of Ne to CO, but does not describe the ground state geometry as well as the SAPT surface.

The three-dimensional ground state potential energy surfaces for He–Cl2, Ne–Cl2, and Ar–Cl2 have been calculated using the single and double excitation coupled-cluster approach with noniterative perturbational treatment of triple excitations [CCSD(T)]. Calculations have been performed with the augmented correlation consistent triple zeta basis sets supplemented with an additional set of bond functions. Single point calculations for approximate minima have also been performed with several other basis sets including the quadruple zeta basis set (aug-cc-pVQZ) with bond functions. For He–Cl2 and Ar–Cl2 the CCSD(T) results show that the linear configuration is lower in energy than the T-shaped one. For Ne–Cl2 the CCSD(T) approach predicts the T-shaped configuration to be lower in energy. The linear configuration has been found to be more sensitive than the T-shaped one to the changes of the Cl–Cl bond length with the interaction becoming weaker when the Cl–Cl bond length is shortened from its equilibrium value...

The potential energy surfaces for the ground state of the Ar–HCN complex have been calculated at several levels of theory, including the single and double excitation coupled-cluster method with noniterative perturbational treatment of triple excitation CCSD(T). Calculations have been performed using the augmented correlation-consistent polarized triple zeta basis set supplemented with bond functions (aug-cc-pVTZ+bf). The global minimum with a well depth of approximately 141 cm−1 has been found for the linear Ar–H–C–N geometry (Θ=0.0°) with the distance R between the Ar atom and the center of mass of the HCN molecule equal to 8.52a0. In addition, the potential energy surface has been found to contain a long channel that extended from the bent configuration at R=7.39a0 and Θ=59.7° (a well depth of 126 cm−1) toward the T-shaped configuration with R=7.16a0 and Θ=107.5° (a well depth of 121 cm−1). The interaction energies have been analyzed using perturbation theory of intermolecular forces. The location of th...

Single and double excitation coupled-cluster approach with noniterative perturbational treatment of triple excitations [CCSD(T)] has been used to calculate the ground state potential energy surfaces for He–F2, Ne–F2, and Ar–F2 van der Waals complexes. Calculations have been performed with the augmented correlation consistent triple zeta basis sets supplemented with an additional set of bond functions (aug-cc-pVTZ+bf). Single point calculations for approximate minima have also been performed with a larger quadruple zeta basis set (aug-cc-pVQZ+bf). For He–F2 and Ar–F2 the CCSD(T) results show that the linear configuration is lower in energy than the T-shaped one. For Ne–F2 the CCSD(T) interaction energies of the two configurations are virtually the same. The linear configuration of each complex has been found to be much more sensitive than the T-shaped one to the changes of the F–F bond length with the interaction becoming weaker when the F–F bond length is shortened from its equilibrium value and stronger ...

The many-body exchange effects up to the 5-body have been analyzed in terms of possible mechanisms by which the intermolecular electron exchange is carried out. The terms corresponding to single (SE), triple (TE), double (DE), and quadruple (QE) exchanges are identified, and their diagrammatic interpretation given. It is demonstrated that they require different physical interpretations, as well as display different angular and radial behaviors. The 3-body SE and TE terms were calculated ab initio, and analyzed for a variety of geometries of the He 2 CO 2 cluster. The anisotropy of SE over the wide range of configurations is consistent with the electrostatic model of the exchange quadrupole of He 2 , interacting with the permanent quadrupole of CO 2 . The behavior of TE may be rationalized by considering the Pauli-principle-induced distortion of the monomers involved. The influence of the CO 2 asymmetric stretch on the SE, TE, and on the total exchange non-additivity has also been evaluated and discussed. The TE 4-body term in He 3 CO 2 has been calculated and compared with the SE 3-body terms.

Complete polarizabilities and first hyperpolarizabilities (which include zero-point-vibrational averaging and other vibrational corrections) have been calculated at the self-consistent-field and Moller–Plesset second order perturbation levels of approximation for CH4, CF4, and CCl4. As well as the static values, α(−ω;ω), β(−ω;ω,0), and β(−2ω;ω,ω) have also been determined. The values of β(−2ω;ω,ω) for CCl4 are germane to a proposed standard for the determination of nonlinear optical properties in solution. For CCl4, our best estimate of β(−2ω;ω,ω) at ℏω = 0.040 a.u. is 13.6 a.u., the experimentally-derived gas value at ℏω = 0.043 a.u. is 20.7± 1.6 a.u. This latter value has been used to substantiate the proposed liquid phase value.

The lowest states of Σ and Π symmetry of Rg⋯Cl (Rg=He, Ne, Ar) complexes were investigated using the coupled cluster approach with single, double, and noniterative triple excitations (CCSD(T)) in an extended basis set including bond functions. The Σ states possess deeper minima at shorter interatomic distances than the corresponding Π states. The Σ-Π splittings, which for He⋯Cl and Ar⋯Cl are significantly larger than previously deduced, are mainly due to differences in the exchange repulsion terms. The total energies were dissected into electrostatic, exchange, induction, and dispersion components. The calculated potentials have been used in the calculations of collision properties of Rg⋯Cl systems. Absolute total cross sections, spin-orbit quenching rate constants, and diffusion coefficients were evaluated from both the ab initio and previously available empirical potentials. The performance of ab initio potentials in these calculations proved to be very reasonable.

The potential energy surface for the Ar(1S)+NH(X 3Σ−) interaction is calculated using the supermolecular unrestricted Mo/ller–Plesset (UMP) perturbation theory approach and analyzed via the perturbation theory of intermolecular forces. The global minimum occurs for the approximate T-shaped geometry with Ar skewed toward the H atom at about Θ=67° and R=6.75 a0. Our UMP4 estimate of the well depth of the global minimum is De=100.3 cm−1 and the related ground state dissociation energy obtained by rigid-body diffusion quantum Monte Carlo calculations (RBDQMC) is D0=71.5±0.1 cm−1. These values are expected to be accurate to within a few percent. The potential energy surface also features a wide plateau in the proximity of Ar-N-H collinear geometry, at ca. 7.0 a0. RBDQMC calculations reveal nearly a free rotation of the NH subunit in the complex.

The complexes of a rare gas atom (RG) and a number of open-shell molecules are discussed in the context of the bond character, structural and dynamical properties. The potential energy surfaces of a variety of complexes have been obtained using the combination of highly correlated supermolecular approach and the symmetry-adapted perturbation theory. Complexes of Σ-state species, O2 and NH, display typical non-covalent interactions, similar to closed-shell systems. Complexes of Π-state species are represented by pairs of adiabatic potentials A' and A'' due to removal of degeneracy through the interaction with the RG moiety. The two states may have distinctly different character. The He-CH(X2Π) complex displays an incipient π-bond on its A'' surface, while a regular van der Waals interaction is observed on the A' surface. Interaction of a Π-state chlorine atom with RG gives rise to two potential curves: Σ and Π. The Σ state features an incipient σ bond whereas the Π-state surface reveals a van der Waals interaction. The excited state complex He + Cl2(B3Πu) illustrates a different situation, with both the A' and A'' states fairly close to each other, with only slight indication of the incipient bond.

The article contains information on the scope and effects of environmental and legal audit in the enterprise. The analysis focused on the main environmental issues identified in different types of enterprises. It was pointed out that the identification of discrepancy areas with the environment protection law in force, enables their improvement. The results of the environmental and legal audit aid to minimize the costs of penalties, the amount of which was presented in the article, improve the functioning of the environmental management system and the qualification of market value of enterprise.

The ArHCCH interaction is investigated by the supermolecular Moller-Plesset perturbation theory and coupled-cluster theory in conjunction with the perturbation theory of intermolecular forces. The interaction energy in this cluster is dissected into the fundamental components such as exchange, induction, and dispersion, and the anisotropy of the overall surface is analysed in terms of the angular behaviors of these components. The shape of the PES of ArHCCH is very sensitive to the level of ab initio theory. The coupled-cluster approach which included the single, double, and approximate triple excitations combined with the aug-cc-pvtz basis set supplemented by bond functions was necessary to obtain the best estimates of D e (within ± 5% error) for two minima: the global one for a skew T-configuration (118 cm −1 ), and a secondary one for the collinear arrangement (115 cm −1 ). The PES generated at a lower level of calculation was used in diffusion quantum Monte Carlo (DMC) calculations of the ground and first excited bending vibrational state of the cluster. The expectation values of the coordinates and rotational constants are provided for the ground state. DMC calculations are relatively unsensitive to the details of the PES. The nature and decomposition of three-body interactions in the related cluster Ar 2 HCCH were also investigated.

The dependence of the two-body and three-body interactions in the ArnCO2 cluster upon the intramolecular asymmetric stretching coordinate of CO2 is studied by the ab initio method. In the T-shaped binary complex Ar–CO2, the influence of the components of the interaction energy on the shift of the asymmetric stretching frequency of CO2 (ν3) is estimated within a one-dimensional vibrational model and compared with the experimental data of Sperhac, Weida, and Nesbitt [J. Chem. Phys. 104, 2202 (1996)]. The interaction energy is dissected into Heitler–London, induction, and dispersion energies and their respective intrasystem correlation corrections. The redshift represents a delicate balance of these effects on the v=0 and v=1 levels. The highly correlated treatment is required to describe the dependence of two-body potential upon the stretching coordinate. The supermolecular coupled cluster calculations with the single, double, and noniterative triple excitations reproduce the shift observed by Sperhac et al. with excellent accuracy. In the Ar2CO2 trimer with the two Ar atoms in equatorial positions, the influence of the three-body interaction components on the v=0 and v=1 levels is analyzed. A model of the three-body potential, including three nonadditive components, exchange, induction, and dispersion is applied. It describes the departure from additivity of the two-body shifts observed by Sperhac et al. with excellent accuracy. The analytical models of the energy components are also discussed.

A potential energy surface for the Ar(1S)+O2(X 3Σg−) interaction is calculated using the supermolecular unrestricted Mo/ller–Plesset (UMP) perturbation theory and analyzed via the perturbation theory of intermolecular forces. The global minimum occurs for the T-shaped geometry, around 6.7 a0. Our UMP4 estimate of the well depth of the global minimum is De=117 cm−1 and the related ground state dissociation energy obtained by diffusion Monte Carlo calculations is 88 cm−1. These values are expected to be accurate to within a few percent. The potential energy surface also reveals a local minimum for the collinear geometry at ca∼7.6 a0. The well depth for the secondary minimum at the UMP4 level is estimated at De=104 cm−1. The minima are separated by a barrier of 23 cm−1. The global minimum is determined by the minimum in the exchange repulsion in the direction perpendicular to the O–O bond. The secondary, linear minimum is enhanced by a slight flattening of the electron density near the ends of the interoxyge...

The theory of relaxed density matrices has been developed for the calculation of second-order response properties at third-order Mo/ller–Plesset (MP3) and linearized coupled cluster double excitation (L-CCD) levels of theory. The ensuing algorithm is applied to the determination of the isotropic and anisotropic nuclear magnetic shielding constants and magnetizabilities for thirteen molecules (H2, N2, F2, HF, CO, HCN, HNC, H2O, NH3, H2O2, HCHO, CH4, and HCCH). The method uses conventional gauge-variant orbitals but, by using large basis sets, produces results which are equivalent to those found with gauge-including orbitals. In general the L-CCD values of the magnetizabilities are consistent with those obtained with multiconfigurational self-consistent-field (MCSCF) methods for molecules which have been treated by this method. For the nuclear shieldings, when there is a difference between L-CCD and MP3, the former gives results closer to the coupled-cluster singles and doubles level treatment augmented with a perturbation correction for connected triple excitations [CCSD(T)] which is our reference point. Again the results for the shieldings at the L-CCD level are quite good. We also use the paramagnetic components of the shieldings and magnetizabilities to determine the spin-rotation constants and rotational g tensors, respectively. These quantities are important since they may be compared more directly with experiment than the magnetizabilities and shieldings.

We analyze the many-body exchange interactions in atomic and molecular clusters as they arise in the supermolecular SCF and MP2 approaches. A rigorous formal setting is provided by the symmetry-adapted perturbation theory. Particular emphasis is put on the decomposition into the single exchange (SE) and triple exchange (TE) terms, at the SCF and correlated levels. We also propose a novel approach, whereby selected SE nonadditive exchange terms are evaluated indirectly, as differences of the two-body SAPT corrections arising between the components of the trimer treated as a complex of a dimer and a monomer (pseudodimer approach). This provides additional insights into the nature of various nonadditive effects, an interpretation of supermolecular interaction energies, and may serve as a viable alternative for the calculation of some SE terms.

Ab initio calculations using unrestricted Mo/ller–Plesset perturbation theory to fourth order (UMP-4) were carried out for the interaction of He with the B 3Π0u+ state of Cl2. Also, more reliable unrestricted coupled cluster singles, doubles, and noniterative triples (UCCSD(t)) calculations were performed for several points on the B electronic state surface and were used to scale the UMP-4 points. Exp-6 type two center potential energy functions were fitted to the modified UMP-4 points (B state) to construct an analytical three-dimensional potential energy surface. An r (Cl–Cl separation) dependence was incorporated in the B state potential energy surface to allow the calculation of HeCl2 properties in different vibrational states so that vibrational predissociation rates could be calculated. Excitation spectra, predissociation lifetimes, and rotational product distributions were calculated and compared to the available experimental data. It was found that the calculated B←X, 8←0 spectrum is in good agree...

Potential energy surfaces for the 2A′ and 2A″ states of the He(1S)–CH(X 2Π) complex were calculated using supermolecular unrestricted Mo/ller–Plesset perturbation theory and analyzed via the relevant perturbation theory of intermolecular forces. It has been found that the two states are distinctly different. The potential energy surface (PES) of the A″ state has only a single and relatively deep minimum of De≊335 μEh for the T‐shaped geometry, at R=5.0 a0 and Θ=100°. The position of this minimum is determined by the exchange repulsion which is substantially reduced at this geometry. The minimum is unusually deep for a complex of He, and it can be viewed as an example of an incipient chemical bond. In contrast, the A′ state’s PES represents a typical van der Waals interaction which is characterized by two similarly deep minima. The shape and location of these minima are determined primarily by the anisotropy of the dispersion component. The first minimum occurs for the collinear He–C–H arrangement, at R≊7....

Potential energy surface for the He(1S)+O2(X 3Σ−g) interaction is calculated using the supermolecular unrestricted Mo/ller‐Plesset perturbation theory approach and is analyzed via the perturbation theory of intermolecular forces. The latter has been generalized to provide a decomposition of the interaction energies into electrostatic, exchange, induction, and dispersion constituents for monomers described by unrestricted Hartree–Fock determinants. The global minimum occurs for the T‐shaped geometry, around 6.0a0. Our UMP4 estimate of the well depth of the global minimum is De=27.7 cm−1. This value is expected to be accurate to within a few percent. The potential energy surface reveals also a local minimum for the collinear geometry at about 7.0a0. The well depth for the secondary minimum is estimated at De=25.5 cm−1(UMP4) and is expected to be accurate within a few percent. The minima are separated by a barrier of 7.5 cm−1. The energy partitioning reveals that the origin of interaction in this complex is ...

The effects of a uniform static electric field on the NMR shielding and magnetizability of H 2 , N 2 , HF, and CO are reported. The appropriate defining quantities are the shielding and magnetizability polarizabilities and these are calculated in a mixed numeric-analytic scheme with allowance for electron correlation via third-order Moller-Plesset (MP3) theory or linearized coupled cluster double excitation (L-CCD) theory. This is the first time that these theories have been applied to these properties. Our primary conclusion for the shielding polarizabilities is that, with the exception of H 2 , the use of coupled cluster theory is necessary to establish the definitive values for these properties because of their extreme sensitivity to electron correlation. For the magnetizability polarizabilities we find the MP3 values to be in better agreement with the L-CCD results than the MP2 values are.

Full geometry optimizations have been performed at the MP2 level of theory using the 6-31G(d,p) basis set for the five common nucleic acid bases (uracil, thymine, cytosine, adenine, and guanine) and three related bases (fluorouracil, 5-methylcytosine, and hypoxanthine). Several electric properties were subsequently calculated using the optimized geometries and the larger polarized basis sets of Sadlej. Including electron correlation decreases the magnitude of the dipole moments by 10−15% for every base except adenine. In all cases, inclusion of electron correlation increases the mean polarizability by 8−12% and also increases the polarizability anisotropy by as much as 14−20%. Results for structurally similar bases were compared in order to qualitatively study the effects of functional group substitution on geometries and electric properties.

Sierka E., Cybulski M. (2013). Optymalizacja gospodarki odpadami w przedsiębiorstwie. In: WYBRANE ZAGADNIENIA INŻYNIERII PRODUKCJI (ed. Kardaś E.), Częstochowa, 55-62.

The partitioning of interaction energy between a closed‐shell and an open‐shell system is proposed. This allows us to describe the unrestricted Mo/ller–Plesset interaction energy as a sum of fundamental contributions: electrostatic, exchange, induction and dispersion. The supermolecular energies derived within unrestricted Mo/ller–Plesset perturbation theory are analyzed in terms of perturbation theory of intermolecular forces. The latter has been generalized to allow for the description of monomer wave functions within the unrestricted Hartree–Fock approach. The method is applied to the potential energy surfaces for the first excited triplet states, 3A′ and 3A″, of the He+Cl2(3Πu) complex. The 3A′ and 3A″ potential energy surfaces have different shapes. The lower one, 3A′, has a single minimum for the T‐shaped structure. The higher one, 3A″, has the global minimum for the T‐shaped structure and the secondary minimum for a linear orientation. The calculated well depth for the 3A′ state is 31.1 cm−1 at the...