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2. Dynamic Permittivity Measurement of Ground-Tire Rubber (GTR) during Microwave-Assisted Devulcanization

Author

European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Gobierno de Aragón, Consejo Superior de Investigaciones Científicas (España), Pérez-Campos, Rafael, Fayos-Fernández, José, Monzó-Cabrera, J., Martín Salamanca, Fernando, López Valentín, Juan, Catalá-Civera, José M., Plaza-Gonzalez, Pedro, Sánchez-Marín, J. R., European Commission, Ministerio de Ciencia, Innovación y Universidades (España), Gobierno de Aragón, Consejo Superior de Investigaciones Científicas (España), Pérez-Campos, Rafael, Fayos-Fernández, José, Monzó-Cabrera, J., Martín Salamanca, Fernando, López Valentín, Juan, Catalá-Civera, José M., Plaza-Gonzalez, Pedro, and Sánchez-Marín, J. R.

Abstract

Many efforts are being made to find innovative ways of recycling rubber from end-of-life tires (ELTs), also called ground tire Rubber (GTR). Recycling through devulcanization allows the reintroduction of rubber back into the manufacturing industry. Such a process requires providing enough energy to break the sulfur links, while preventing damage to the polymeric chain. Microwave heating is controllable, efficient, and it does not rely on conventional heating mechanisms (conduction, convection) which may involve high heating losses, but rather on direct dielectric heating. However, to adequately control the microwave-assisted devulcanization performance, a thorough knowledge of the GTR permittivity versus temperature is required. In this work, GTR permittivity was monitored during its devulcanization. A resonant technique based on a dual-mode cylindrical cavity was used to simultaneously heat rubber and measure its permittivity at around 2 GHz. The results show sharp changes in the GTR permittivity at 160 and 190 °C. After the GTR cooled down, a shifted permittivity evidences a change in the GTR structure caused by the devulcanization process. Microwave-assisted devulcanization effectiveness is proven through time-domain nuclear magnetic resonance (NMR) measurements, by verifying the decrease in the cross-link density of processed GTR samples compared to the original sample.

Published
2022

9. Abstracts of the 6th FECS Conference 1998 Lectures

Author

Rowland, F. Sherwood, Blake, Donald R., Larsen, B. R., Lindskog, Anne, Peterson, Peter J., Williams, W. Peter, Wallington, T. J., Pilling, M. J., Carslaw, N., Creasey, D. J., Heard, D. E., Jacobs, P., Lee, J., Lewis, A. C., McQuaid, J. B., Stockwell, William R., Frank, Hartmut, Sacco, P., Cocheo, V., Lynge, E., Andersen, A., Nilsson, R., Barlow, L., Pukkala, E., Nordlinder, R., Boffetta, P., Grandjean, P., Heikkil, P., Hürte, L. G., Jakobsson, R., Lundberg, I., Moen, B., Partanen, T., Riise, T., Borowiak, A., De Saeger, E., Schnitzler, K. G., Gravenhorst, G., Jacobi, H. W., Moelders, S., Lammel, G., Busch, G., Beese, F. O., Dentener, F. J., Feichter, J., Fraedrich, K., Roelofs, G. J., Friedrich, R., Reis, S., Voehringer, F., Simpson, D., Moussiopoulos, N., Sahm, P., Tourlou, P. M., Salmons, R., Papameletiou, D., Maqueda, J. M., Suhr, Per B., Bell, W., Paton-Walsh, C., Woods, P. T., Partridge, R. H., Slemr, J., Slemr, F., Schmidbauer, N., Ravishankara, A. R., Jenkin, Michael E., de Leeuw, G., van Eijk, A. M. J., Flossmann, A. I., Wobrock, W., Mestayer, P. G., Tranchant, B., Ljungström, E., Karlsson, R., Larsen, S. E., Roemer, M., Builtjes, P. J. H., Koffi, Brigitte, Koffi, Ernest N’Dri, De Saeger, Emile, Ro-Poulsen, H., Mikkelsen, T. N., Hummelshøj, P., Hovmand, M. F., Simoneit, Bernd R. T., van der Meulen, A., Meyer, Michael B., Berndt, T., Böge, O., Stratmann, F., Cass, Glen R., Harrison, Roy M., Shi, Ji Ping, Hoffmann, T., Warscheid, B., Bandur, R., Marggraf, U., Nigge, W., Kamens, Richard, Jang, Myoseon, Strommen, Mike, Chien, Chao-Jung, Leach, Keri, Ammann, M., Kalberer, M., Arens, F., Lavanchy, V., Gâggeler, H. W., Baltensperger, U., Davies, J. A., Cox, R. A., Alonso, S. García, Pastor, R. Pérez, Argüello, Gustavo A., Willner, Helge, Berndt, T., Böge, O., Bogillo, V. I., Pokrovskiy, V. A., Kuraev, O. V., Gozhyk, P. F., Bolzacchini, E., Bruschi, M., Fantucci, P., Meinardi, S., Orlandi, M., Rindone, B., Bolzacchini, Ezio, Bohn, Birger, Rindone, Bruno, Bruschi, Maurizo, Zetzsch, Cornelius, Brussol, C., Duane, M., Larsen, B., Carlier, P., Kotzias, D., Caracena, A. Baeza, Aznar, A. Miñana, Ferradás, E. González, Christensen, C. S., Skov, H., Hummelshøj, P., Jensen, N. O., Lohse, C., Cocheo, V., Sacco, P., Chatzis, C., Cocheo, V., Sacco, P., Boaretto, C., Quaglio, F., Zaratin, L., Pagani, D., Cocheo, L., Cocheo, Vincenzo, Asnar, Agustin Minana, Baldan, Annerita, Ballesta, Pascual P., Boaretto, Caterina, Caracena, Antonia B., Ferradas, Enrique Gonzalez, Gonzalez-Flesca, Nobert, Goelen, Eddie, Hansen, Asger B., Sacco, Paolo, De Saeger, Emile, Skov, Henrik, Consonni, V., Gramatica, P., Santagostino, A., Galvani, P., Bolzacchini, E., Consonni, Viviana, Gramatica, Paola, Todeschini, Roberto, Dippel, G., Reinhardt, H., Zellner, R., Dämmer, K., Bednarek, G., Breil, M., Zellner, R., Febo, A., Allegrini, I., Giliberti, C., Perrino, C., Fogg, P. G. T., Geiger, H., Barnes, I., Becker, K. H., Maurer, T., Geyskens, F., Bormans, R., Lambrechts, M., Goelen, E., Giese, Martina, Frank, Hartmut, Glasius, M., Hornung, P., Jacobsen, J. K., Klausen, H. S., Klitgaard, K. C., Møller, C. K., Petersen, A. P. F., Petersen, L. S., Wessel, S., Hansen, T. S., Lohse, C., Boaretto, E., Heinemeier, J., Glasius, M., Di Bella, D., Lahaniati, M., Calogirou, A., Jensen, N. R., Hjorth, J., Kotzias, D., Larsen, B. R., Gonzalez-Flesca, N., Cicolella, A., Bates, M., Bastin, E., Gurbanov, M. A., Akhmedly, K. M., Balayev, V. S., Haselmann, K. F., Ketola, R., Laturnus, F., Lauritsen, F. R., Grøn, C., Herrmann, H., Ervens, B., Reese, A., Umschlag, Th., Wicktor, F., Zellner, R., Herrmann, H., Umschlag, Th., Müller, K., Bolzacchini, E., Meinardi, S., Rindone, B., Jenkin, Michael E., Hayman, Garry D., Jensen, N. O., Courtney, M., Hummelshøj, P., Christensen, C. S., Larsen, B. R., Johnson, Matthew S., Hegelund, Flemming, Nelander, Bengt, Kirchner, Frank, Klotz, B., Barnes, Ian, Sørensen, S., Becker, K. H., Etzkorn, T., Platt, U., Wirtz, K., Martín-Reviejo, M., Laturnus, Frank, Martinez, E., Cabañas, B., Aranda, A., Martín, P., Salgado, S., Rodriguez, D., Masclet, P., Jaffrezo, J. L., Hillamo, R., Mellouki, A., Le Calvé, S., Le Bras, G., Moriarty, J., O’Donnell, S., Wenger, J., Sidebottom, H., Mingarrol, M. T. Bomboi, Cosin, S., Pastor, R. Pérez, Alonso, S. García, Sanz, M. J., Bravo, I., Gonzalez, D., Pérez, M. A., Mustafaev, Islam, Mammadova, Saida, Noda, J., Hallquist, M., Langer, S., Ljungström, E., Nohara, K., Kutsuna, S., Ibusuki, T., Oehme, Michael, Kölliker, Stephan, Brombacher, Stephan, Merz, Leo, Pastor, R. Pérez, Alonso, S. García, Cabezas, A. Quejido, Peeters, J., Vereecken, L., El Yazal, J., Pfeffer, Hans-Ulrich, Breuer, Ludger, Platz, J., Nielsen, O. J., Sehested, J., Wallington, T. J., Ball, J. C., Hurley, M. D., Straccia, A. M., Schneider, W. F., Pérez-Casany, M. P., Nebot-Gil, I., Sánchez-Marín, J., Putz, E., Folberth, G., Pfister, G., Weissflog, L., Elansky, N. P., Sørensen, Søren, Barnes, Ian, Becker, K. H., Shao, M., Heiden, A. C., Kley, D., Rockel, P., Wildt, J., Silva, G. V. A., Vasconcelos, M. T., Fernandes, E. O., Santos, A. M. S., Skov, Henrik, Hansen, Asger, Løfstrøm, Per, Lorenzen, Gitte, Stabel, J. R., Wolkoff, P., Pedersen, T., Strom, A. B., Skov, Henrik, Hertel, Ole, Jensen, Finn Palmgren, Hjorth, Jens, Galle, Bosse, Wallin, Svante, Theloke, J., Libuda, H. G., Zabel, F., Touaty, Muriel, Bonsang, Bernard, Ullerstam, M., Langer, S., Ljungström, E., Wenger, John, Bonard, Amélie, Manning, Marcus, Nolan, Sinéad, O’Sullivan, Niamh, Sidebottom, Howard, Wenger, John, Collins, Eoin, Moriarty, Jennie, O’Donnell, Sinéad, Sidebottom, Howard, Wenger, John, Collins, Eoin, Moriarty, Jennie, O’Donnell, Sinéad, Sidebottom, Howard, Wenger, John, Sidebottom, Howard, Chadwick, Paul, O’Leary, Barbara, Treacy, Jack, Wolkoff, Peder, Clausen, Per A., Wilkins, Cornelius K., Hougaard, Karin S., Nielsen, Gunnar D., Zilinskis, Viktors, Jansons, Guntis, Peksens, Aigars, Lazdins, Agris, Arinci, Y. V., Erdöl, N., Ekinci, E., Okutan, H., Manlafalioglu, I., Bakeas, Evangelos B., Siskos, Panayotis A., Viras, Loizos G., Smirnioudi, Vasiliki N., Bottenheim, Jan W., Biesenthal, Thomas, Gong, Wanmin, Makar, Paul, Delmas, Véronique, Menard, Tamara, Tatry, Véronique, Moussafir, Jacques, Thomas, Dominique, Coppalle, Alexis, Ellermann, Thomas, Hertel, Ole, Skov, Henrik, Frohn, Lise, Manscher, Ole H., Friis, Jørgen, Girgzdiene, Rasa, Girgzdys, Aloyzas, Gurevich, N. A., Gårdfeldt, Katarina, Langer, Sarka, Hermans, C., Vandaele, A. C., Carleer, M., Fally, S., Colin, R., Bernath, P. F., Jenouvrier, A., Coquart, B., Mérienne, M. -F., Hertel, Ole, Frohn, Lise, Skov, Henrik, Ellermann, Thomas, Huntrieser, H., Schlager, H., Feigl, C., Kemp, Kåre, Palmgren, Finn, Kiilsholm, Sissi, Rasmussen, Alix, Sørensen, Jens Havskov, Klemm, Otto, Lange, Holger, Larsen, René Wugt, Larsen, Niels Wessel, Nicolaisen, Flemming, Sørensen, Georg Ole, Beukes, Jon Are, Larsen, Poul Bo, Jensen, Steen Solvang, Fenger, Jes, de Leeuw, Gerrit, Kunz, Gerard, Cohen, Leo, Schlünzen, Heinke, Muller, Frank, Schulz, Michael, Tamm, Susanne, Geernaert, Gary, Hertel, Ole, Pedersen, Britta, Geernaert, Lise Lotte Sørensen, Lund, Søren, Vignati, Elisabetta, Jickells, Tim, Spokes, Lucinda, Matei, C., Jinga, O. A., Jinga, D. C., Moliner, R., Braekman-Danheux, C., Fontana, A., Suelves, I., Thieman, T., Vassilev, S., Skov, Henrik, Hertel, Ole, Zlatev, Zahari, Brandt, Jørgen, Bastrup-Birk, Annemarie, Ellermann, Thomas, Frohn, Lise, Vandaele, A. C., Hermans, C., Carleer, M., Tsouli, A., Colin, R., Windsperger, Andreas M., Turi, Kristina, Dworak, Oliver, Zellweger, C., Weingartner, E., Rüttimann, R., Hofer, P., Baltensperger, U., Ziv, A., Iakovleva, E., Palmgren, F., Berkovicz, R., Skov, H., Alastuey, A., Querol, X., Chaves, A., Lopez-Soler, A., Ruiz, C., Andrees, J. M., Allegrini, I., Febo, A., Giusto, M., Angeloni, M., Di Filippo, P., D’Innocenzio, F., Lepore, L., Marconi, A., Arshinov, M. Yu., Belan, B. D., Davydov, D. K., Kovaleskii, V. K., Plotinov, A. P., Pokrovskii, E. V., Sklyadneva, T. K., Tolmachev, G. N., Arshinov, M. Yu., Belan, B. D., Sklyadneva, T. K., Behnke, Wolfgang, Elend, Manfred, Krüger, Ulrich, Zetzsch, Cornelius, Belan, B. D., Arshinov, M. Yu., Davydov, D. K., Kovalevskii, V. K., Plotnikov, A. P., Pokrovskii, E. V., Rasskazchikova, T. M., Sklyadneva, T. K., Tolmachev, G. N., Belan, B. D., Arshinov, M. Yu., Simonenkov, D. V., Tolmachev, G. N., Bilde, Merete, Aker, Pamela M., Börensen, C., Kirchner, U., Scheer, V., Vogt, R., Ellermann, T., Geernaert, L. L. S., Pryor, S. C., Barthelmie, R. J., Feilberg, Anders, Nielsen, Torben, Kamens, Richard M., Freitas, M. C., Marques, A. P., Reis, M. A., Alves, L. C., Ilyinskikh, N. N., Ilyinskikh, I. N., Ilyinskikh, E. N., Johansen, Keld, Stavnsbjerg, Peter, Gabrielsson, Pär, Bak, Flemming, Andersen, Erik, Autrup, Herman, Kamens, Richard, Jang, Myoseon, Strommen, Michael, Leach, Keri, Kirchner, U., Scheer, V., Börensen, C., Vogt, R., Igor, Komov, Svjatoslav, Galiy, Anatoliy, Burlak, Komov, I. L., Istchenko, A. A., Lourenço, M. G., MacTavish, D., Sirois, A., Masclet, Pierre, Jaffrezo, Jean Luc, van der Meulen, A., Milukaite, A., Morkunas, V., Jurgutis, P., Mikelinskiene, A., Nielsen, Torben, Feilberg, Anders, Binderup, Mona Lise, Pineda, M., Palacios, J. M., Garcia, E., Cilleruelo, C., Moliner, R., Popovitcheva, O. B., Trukhin, M. E., Persiantseva, N. M., Buriko, Yu, Starik, A. M., Demirdjian, B., Suzanne, J., Probst, T. U., Rietz, B., Alfassi, Z. B., Pokrovskiy, V. A., Zenobi, R., Bogatyr’ov, V. M., Gun’ko, V. M., Querol, X., Alastuey, A., Lopez-Soler, A., Mantilla, E., Plana, F., Artiño, B., Rauterberg-Wulff, A., Israël, G. W., Rocha, Teresa A. P., Duarte, Armando C., Röhrl, Andreas, Lammel, Gerhard, Spindler, G., Müller, K., Herrmann, H., Strommen, Michael R., Vignati, Elisabetta, de Leeuw, Gerrit, and Berkowicz, Ruwim

Published
1998
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14. The electronic spectrum of SiH4: Jahn-Teller Rydberg series.

Author

Velasco, A. M., Lavín, C., Sánchez de Merás, A. M. J., and Sánchez Marín, J.

Subjects
ELECTRON spectroscopy, SILICON compounds, JAHN-Teller effect, RYDBERG states, IONIZATION (Atomic physics), EQUATIONS of motion, DIPOLE moments
Abstract

The aim of the present theoretical work is to provide data necessary for a better understanding of the electronic spectrum of the silane molecule, which is affected by the Jahn-Teller effect. By selecting an adequate distorted C2v geometry of SiH4, the three lower Koopmans ionization potentials are evaluated with the equation of motion coupled cluster of singles and doubles method. Vertical excitation energies for the different Rydberg series converging to the three Jahn-Teller components are inferred from ab initio coupled cluster linear response calculations. Absorption oscillator strengths for dipole-allowed electronic transitions are also determined with the molecular-adapted quantum defect orbital methodology. Predictions of new spectroscopic data on SiH4 are reported. [ABSTRACT FROM AUTHOR]

Published
2011
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15. Lower Rydberg series of methane: A combined coupled cluster linear response and molecular quantum defect orbital calculation.

Author

Velasco, A. M., Pitarch-Ruiz, J., Sánchez de Merás, Alfredo M. J., Sánchez-Marín, J., and Martin, I.

Subjects
RYDBERG states, ENERGY levels (Quantum mechanics), ATOMIC spectra, QUANTUM defect theory, QUANTUM theory, ATOMIC spectroscopy, NUCLEAR excitation
Abstract

Vertical excitation energies as well as related absolute photoabsorption oscillator strength data are very scarce in the literature for methane. In this study, we have characterized the three existing series of low-lying Rydberg states of CH4 by computing coupled cluster linear response (CCLR) vertical excitation energies together with oscillator strengths in the molecular-adapted quantum defect orbital formalism from a distorted Cs geometry selected on the basis of outer valence green function calculations. The present work provides a wide range of data of excitation energies and absolute oscillator strengths which correspond to the Rydberg series converging to the three lower ionization potential values of the distorted methane molecule, in energy regions for which experimentally measured data appear to be unavailable. [ABSTRACT FROM AUTHOR]

Published
2006
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17. Self-consistent intermediate Hamiltonians: A coupled cluster type formulation of the singles and doubles configuration interaction matrix dressing.

Author

Nebot-Gil, I., Sánchez-Marín, J., Malrieu, J. P., Heully, J. L., and Maynau, D.

Subjects
*ELECTRON configuration, *MOLECULAR orbitals, *HAMILTONIAN systems
Abstract

This paper presents a new self-consistent dressing of a singles and doubles configuration interaction matrix which insures size-consistency, separability into closed-shell subsystems if localized molecular orbitals (MOs) are used, and which includes all fourth order corrections. This method yields, among several schemes, a reformulation of the coupled cluster method, including fully the cluster operators of single and double excitations, and partially those of the triples (Bartlett’s algorithm named CCSDT-1a). Further improvement can be easily included by adding exclusion principle violating corrections. Since it leads to a matrix diagonalization, the method behaves correctly in case of near degeneracies between the reference determinant and some doubles. Due to its flexibility this formulation offers the possibility of consistent combination with less expensive treatments for the study of very large systems. © 1995 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
1995
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19. Ab Initio Study on the Mechanism of Tropospheric Reactions of the Nitrate Radical with Alkenes: Ethene

Author

Tomás-Vert F, Nebot-Gil I, Pérez-Casany Mp, Martínez-Ataz E, Cabañas-Galán B, Aranda-Rubio A, and Sánchez-Marín J

Subjects
chemistry.chemical_classification, chemistry.chemical_compound, Atomic orbital, Chemistry, Nitric acid, Alkene, Computational chemistry, Organic Chemistry, Potential energy surface, Ab initio, Electron, Basis set, Adduct
Abstract

A mechanism for the reaction of the NO(3) radical with the simplest alkene, ethene, is proposed. The mechanism involves three paths leading to three main different products: oxirane, ethanal, and nitric acid. The three paths start from the same initial intermediate, an NO(3)-ethene adduct. The calculated energy barriers show that the oxirane is the product kinetically more favored. Initial analysis of the potential energy surface was made at AM1 level. Then, the geometries and characterization of the found stationary points on the surface were refined at ROHF level with a 6-31G basis set. Further refinement was carried out at CASSCF level with the same basis set, and an active space was built with five active electrons in six active orbitals.

Published
1998
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21. Modelization of the $$\hbox {H}_{2}$$ adsorption on graphene and molecular dynamics simulation.

Author

Faginas-Lago, N., Yeamin, Md, Sánchez-Marín, J., Cuesta, I., Albertí, M., and Sánchez de Merás, Alfredo

Subjects
MOLECULAR dynamics, GRAPHENE, PHYSISORPTION, MOLECULES, ATOMS
Abstract

In the search for efficient molecular dynamics simulation models both simplicity and acceptable accuracy matter. In the present study, a model of the graphene- $$\hbox {H}_2$$ physisorption system is used to explore its performance and limitations under canonical NVT and microcanonical NVE simulation conditions. The model implies several simplifications that can be summarized in (a) a single ideal planar frozen graphene-like layer of C atoms, (b) rigid rotor $$\hbox {H}_2$$ molecules and (c) interaction potentials written as C-H and $$\hbox {H}_2$$ - $$\hbox {H}_2$$ site-site Improved Lennard-Jones potentials parameterized to reproduce DFT calculations. This model can be used in a variety of molecular dynamics simulation conditions, both in NVT and NVE ensembles. Such simulations lead to the formation of a single layer of adsorbed $$\hbox {H}_2$$ molecules in dynamically stable equilibrium with a fluid-phase region. In addition, the incipient formation of secondary layers for high-density conditions is also observed. Some properties as average pressure, temperatures and fluid-phase densities are discussed as well as possible improvements of the model. [ABSTRACT FROM AUTHOR]

Published
2017
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26. Low-Lying Rydberg States of HCl

Author

Pitarch-Ruiz, J., primary, Sánchez de Merás, A., additional, Sánchez-Marín, J., additional, Velasco, A. M., additional, Lavín, C., additional, and Martín, I., additional

Published
2008
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34. A theoretical study of the rotational structure of the ε(0,0) band of NO.

Author

Velasco, A. M., Lavín, C., Martin, I., Vega, M. V., Pitarch‐Ruiz, J., and Sánchez‐Marín, J.

Subjects
NITRIC oxide, NITROGEN compounds, ELECTRIC discharges, INTERSTELLAR molecules, NITROSO compounds, INTERSTELLAR medium
Abstract

This study has been focused on the ε(0,0) band of the nitric oxide molecule, associated with the absorption electronic transition D2Σ+←X 2Π, in the energetic vacuum ultraviolet region. A temperature of 295 K has been considered. The Molecular Quantum Defect Orbital (MQDO) methodology, with which reliable spectroscopic data have been reached in the γ(0,0), δ(0,0), and δ(1,0) bands of the same molecule, has also been used for these calculations. We hope that the present results might be of straightforward use in atmospheric and interstellar chemistry. © 2009 Wiley Periodicals, Inc. Int J Quantum Chem, 2010 [ABSTRACT FROM AUTHOR]

Published
2010
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37. Full configuration interaction calculation of the low lying valence and Rydberg states of BeH.

Author

Pitarch-Ruiz, J., Sánchez-Marín, J., and Velasco, A. M.

Subjects
*MOLECULES, *WAVE functions, *DIPOLE moments, *QUADRUPOLE moments, *CHANGE
Abstract

The all-electron full configuration interaction (FCI) vertical excitation energies for some low lying valence and Rydberg excited states of BeH are presented in this article. A basis set of valence atomic natural orbitals has been augmented with a series of Rydberg orbitals that have been generated as centered onto the Be atom. The resulting basis set can be described as 4s2p1d/2s1p (Be/H) + 4s4p3d. It allows to calculate Rydberg states up to n= {3,4,5} of the s, p, and d series of Rydberg states. The FCI vertical ionization potential for the same basis set and geometry amounts to 8.298 eV. Other properties such as FCI electric dipole and quadrupole moments and FCI transition dipole and quadrupole moments have also been calculated. The results provide a set of benchmark values for energies, wave functions, properties, and transition properties for the five electron BeH molecule. Most of the states have large multiconfigurational character in spite of their essentially single excited nature and a number of them present an important Rydberg-valence mixing that is achieved through the mixed nature of the particle MO of the single excitations. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2008 [ABSTRACT FROM AUTHOR]

Published
2008
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38. Vertical excitation energies to valence states of DMS and DMSO.

Author

Pérez Mondéjar, V., Yusá, M. J., García Cuesta, I., Merás, A. M. J., and Sánchez-Marín, J.

Subjects
ELECTRONIC excitation, VALENCE (Chemistry), DIMETHYL sulfide, DIMETHYL sulfoxide, PHYSICAL & theoretical chemistry
Abstract

Coupled cluster linear response formalism has been used to compute the vertical excitation energies and oscillator strengths of the lowest valence singlet states of dimethyl sulfide (DMS) and dimethyl sulphoxide (DMSO). Unless for one exception, the results are in very good agreement with experiment, but a new assignment of one DMSO transition is proposed. [ABSTRACT FROM AUTHOR]

Published
2007
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41. The open shell single reference size-consistent self-consistent singles and doubles configuration interaction method: Application to ionization potentials.

Author

Pitarch-Ruiz, J., Sánchez-Marín, J., and Maynau, D.

Subjects
*ELECTRON configuration, *WAVE functions, *CHEMICAL systems
Abstract

In previous works, the size-consistent self-consistent matrix dressing method has been applied to single reference as well as to complete active space singles and doubles configuration interaction. The wave function of the dressed state was assumed to be dominated by a closed shell determinant. Here, the method has been extended to systems where the dressed state is a single-configurational doublet. The method allows for the accurate calculation of energies and wave functions of other electronic states of the same system, having or not the same symmetry, as well as in the case of closed shell systems. This statement has been thoroughly assessed by the calculation of vertical ionization energies corresponding to a few low lying states of HF[sup +] that are compared to full CI results obtained with the cc-pVDZ basis set. The method has been applied, using larger basis sets, to the calculation of vertical ionization potentials (VIP) of HF, H[sub 2]CO, N[sub 2], and NH[sub 3]. The results are compared to experimental VIP values. The effects of selecting different CAS spaces and using pseudonatural adapted MO's obtained from the CASSCF matrix densities are shown and discussed. Mean absolute error (MAE) for the calculated states is about 0.07 eV. The difficulties to improve this precision limit are shown. However, the mean signed absolute errors, that measure accuracy, can be made smaller. Small MAE can be obtained using simultaneously VTZ basis sets and intermediate levels of calculation. The possibility of this effect to be assigned to a fortuitous cancellation of errors is pointed out. © 2000 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
2000
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