Search

Your search keyword '"Taylor, Peter R."' showing total 7 results
Start Over Author "Taylor, Peter R." Topic quantum chemistry
7 results on '"Taylor, Peter R."'

1. One Molecule Suffices: Spectroscopy of Yariv Reagents.

Author

Tang, Chengcheng and Taylor, Peter R.

Subjects
*VISIBLE spectra, *SINGLE molecules, *DENSITY functional theory, *TAUTOMERISM, *MOLECULES
Abstract

We have investigated the structure and spectra (NMR, UV/visible) of several Yariv reagents and models for these species, using both density functional theory (DFT) and approximate coupled‐cluster methods (ADC(2)). We have also studied the formation of dimers and model trimers as a first step to understand the aggregation of these species in aqueous solution. One question that our calculations help resolve is the origin of two strong bands in the visible region of the spectrum: these are confirmed as resulting from enol‐keto tautomerism, and are not a result of aggregation, which was a hypothesis that had been advanced previously. The UV/visible spectrum of the Yariv reagents can be explained entirely in terms of tautomerism within a single molecule – no dimers or clusters are involved. [ABSTRACT FROM AUTHOR]

Published
2023
Full Text
View/download PDF

2. The Dalton quantum chemistry program system

Author

Aidas, Kestutis, Angeli, Celestino, Bak, Keld L., Bakken, Vebjørn, Bast, Radovan, Boman, Linus, Christiansen, Ove, Cimiraglia, Renzo, Coriani, Sonia, Dahle, Pal, Dalskov, Erik K., Ekström, Ulf, Enevoldsen, Thomas, Eriksen, Janus J., Ettenhuber, Patrick, Fernández, Berta, Ferrighi, Lara, Fliegl, Heike, Frediani, Luca, Hald, Kasper, Halkier, Asger, Hättig, Christof, Heiberg, Hanne, Helgaker, Trygve, Hennum, Alf Christian, Hettema, Hinne, Hjertenæs, Eirik, Høst, Stinne, Høyvik, Ida-Marie, Iozzi, Maria Francesca, Jansík, Branislav, Jensen, Hans Jørgen Aa., Jonsson, Dan, Jørgensen, Poul, Kauczor, Joanna, Kirpekar, Sheela, Kjærgaard, Thomas, Klopper, Wim, Knecht, Stefan, Kobayashi, Rika, Koch, Henrik, Kongsted, Jacob, Krapp, Andreas, Kristensen, Kasper, Ligabue, Andrea, Lutnæs, Ola B., Melo, Juan I., Mikkelsen, Kurt V., Myhre, Rolf H., Neiss, Christian, Nielsen, Christian B., Norman, Patrick, Olsen, Jeppe, Olsen, Jógvan Magnus H., Osted, Anders, Packer, Martin J., Pawlowski, Filip, Pedersen, Thomas B., Provasi, Patricio F., Reine, Simen, Rinkevicius, Zilvinas, Ruden, Torgeir A., Ruud, Kenneth, Rybkin, Vladimir V., Sałek, Pawel, Samson, Claire C. M., Sanchez de Merás, Alfredo, Saue, Trond, Sauer, Stephan P. A., Schimmelpfennig, Bernd, Sneskov, Kristian, Steindal, Arnfinn H., Sylvester-Hvid, Kristian O., Taylor, Peter R., Teale, Andrew M., Tellgren, Erik I., Tew, David P., Thorvaldsen, Andreas J., Thøgersen, Lea, Vahtras, Olav, Watson, Mark A., Wilson, David J. D., Ziolkowski, Marcin, Ågren, Hans, Aidas, Kestuti, Angeli, Celestino, Bak, Keld L., Bakken, Vebjørn, Bast, Radovan, Boman, Linu, Christiansen, Ove, Cimiraglia, Renzo, Coriani, Sonia, Dahle, Pål, Dalskov, Erik K., Ekström, Ulf, Enevoldsen, Thoma, Eriksen, Janus J., Ettenhuber, Patrick, Fernández, Berta, Ferrighi, Lara, Fliegl, Heike, Frediani, Luca, Hald, Kasper, Halkier, Asger, Hättig, Christof, Heiberg, Hanne, Helgaker, Trygve, Hennum, Alf Christian, Hettema, Hinne, Hjertenæs, Eirik, Høst, Stinne, Høyvik, Ida-Marie, Iozzi, Maria Francesca, Jansík, Branislav, Jensen, Hans Jørgen Aa, Jonsson, Dan, Jørgensen, Poul, Kauczor, Joanna, Kirpekar, Sheela, Kjærgaard, Thoma, Klopper, Wim, Knecht, Stefan, Kobayashi, Rika, Koch, Henrik, Kongsted, Jacob, Krapp, Andrea, Kristensen, Kasper, Ligabue, Andrea, Lutnæs, Ola B., Melo, Juan I., Mikkelsen, Kurt V., Myhre, Rolf H., Neiss, Christian, Nielsen, Christian B., Norman, Patrick, Olsen, Jeppe, Olsen, Jógvan Magnus H., Osted, Ander, Packer, Martin J., Pawlowski, Filip, Pedersen, Thomas B., Provasi, Patricio F., Reine, Simen, Rinkevicius, Zilvina, Ruden, Torgeir A., Ruud, Kenneth, Rybkin, Vladimir V., Sałek, Pawel, Samson, Claire C. M., de Merás, Alfredo Sánchez, Saue, Trond, Sauer, Stephan P. A., Schimmelpfennig, Bernd, Sneskov, Kristian, Steindal, Arnfinn H., Sylvester-Hvid, Kristian O., Taylor, Peter R., Teale, Andrew M., Tellgren, Erik I., Tew, David P., Thorvaldsen, Andreas J., Thøgersen, Lea, Vahtras, Olav, Watson, Mark A., Wilson, David J. D., Ziolkowski, Marcin, Ågren, Hans, Dipartimento di Chimica, Università degli Studi di Ferrara (UniFE), Centre for Theoretical and Computational Chemistry [Oslo] (CTCC), Department of Chemistry [Oslo], Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO)-Faculty of Mathematics and Natural Sciences [Oslo], University of Oslo (UiO)-University of Oslo (UiO), Groupe Méthodes et outils de la chimie quantique (LCPQ) (GMO), Laboratoire de Chimie et Physique Quantiques (LCPQ), Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Institut de Chimie du CNRS (INC), Department of Physics, Chemistry and Biology, Amsterdam Center for Multiscale Modeling, Vrije Universiteit Amsterdam [Amsterdam] (VU), Laboratory of the Department of Oncology (DEPARTMENT OF ONCOLOGY), Herlev and Gentofte Hospital, Norwegian Meteorological Institute [Oslo] (MET), Teoretisk Kemi, Aarhus University [Aarhus], Centre for Biodiversity Dynamics, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), Karlsruhe Institute of Technology (KIT), Department of Theoretical Chemistry, University Düsseldorf, Department of Mathematics, Tokyo University of Science, Institut Jean-Pierre Bourgin (IJPB), Institut National de la Recherche Agronomique (INRA)-AgroParisTech, Department of Environmental Engineering, Technical University of Denmark [Lyngby] (DTU), Computer Services Networks and Systems, Università degli Studi di Modena e Reggio Emilia (UNIMORE), Hammersmith Hospital, Imperial College, London, Department of Haematology, Niels Bohr Institute [Copenhagen] (NBI), Faculty of Science [Copenhagen], University of Copenhagen = Københavns Universitet (KU)-University of Copenhagen = Københavns Universitet (KU), Centre d'études biologiques de Chizé (CEBC), Centre National de la Recherche Scientifique (CNRS), Centre for Theoretical and Computational Chemistry, University of Tromsø (UiT), Department of Electronics Materials and Devices, Ivanovo State University of Chemistry and Technology, Department of Chemistry [Copenhagen], Institut für Nukleare Entsorgung (INE), Karlsruher Institut für Technologie (KIT), Department of Pharmacology, Skaggs School of Pharmacy & Pharmaceutical Sciences, University of California [San Diego] (UC San Diego), University of California-University of California, School of Chemistry, University of Nottingham, UK (UON), Theoretical Chemistry, Royal Institute of Technology [Stockholm] (KTH ), Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut National des Sciences Appliquées - Toulouse (INSA Toulouse), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS), Norwegian Meteorological Institute, Bakke, Vebjørn, Hjertenaes, Eirik, Høyvik, Ida Marie, Jensen, Hans Jørgen A. a., Kjaergaard, Thoma, Lutnaes, Ola B., Sánchez de Merás, Alfredo, Sylvester Hvid, Kristian O., Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Université Toulouse III - Paul Sabatier (UT3), Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)-Institut de Recherche sur les Systèmes Atomiques et Moléculaires Complexes (IRSAMC), and Université Fédérale Toulouse Midi-Pyrénées-Université Fédérale Toulouse Midi-Pyrénées-Centre National de la Recherche Scientifique (CNRS)-Institut de Chimie du CNRS (INC)

Subjects
Materials Chemistry2506 Metals and Alloys, Software Focus, Ab initio electronic structure methods structure methods, ab initio calculations, VDP::Mathematics and natural science: 400::Chemistry: 440::Theoretical chemistry, quantum chemistry: 444, Computer Science Applications1707 Computer Vision and Pattern Recognition, Quantum chemistry program, Ab-initio methods, Scientific Software, Quantum Chemistry, Molecular properties, Biochemistry, Algorithms, [Electronic Structure Theory], Algorithm, Molecular propertie, [CHIM.THEO]Chemical Sciences/Theoretical and/or physical chemistry, Computational Chemistry, Computational Mathematic, Faculty of Science, Physical and Theoretical Chemistry, VDP::Matematikk og Naturvitenskap: 400::Kjemi: 440::Teoretisk kjemi, kvantekjemi: 444
Abstract

Dalton is a powerful general-purpose program system for the study of molecular electronic structure at the Hartree–Fock, Kohn–Sham, multiconfigurational self-consistent-field, Møller–Plesset, configuration-interaction, and coupled-cluster levels of theory. Apart from the total energy, a wide variety of molecular properties may be calculated using these electronic-structure models. Molecular gradients and Hessians are available for geometry optimizations, molecular dynamics, and vibrational studies, whereas magnetic resonance and optical activity can be studied in a gauge-origin-invariant manner. Frequency-dependent molecular properties can be calculated using linear, quadratic, and cubic response theory. A large number of singlet and triplet perturbation operators are available for the study of one-, two-, and three-photon processes. Environmental effects may be included using various dielectric-medium and quantum-mechanics/molecular-mechanics models. Large molecules may be studied using linear-scaling and massively parallel algorithms. Dalton is distributed at no cost from http://www.daltonprogram.org for a number of UNIX platforms. © 2013 John Wiley & Sons, Ltd. This is an open access article under the terms of the Creative Commons Attribution-NonCommercial-NoDerivs License, (CC BY-NC-ND 3.0)

Published
2014

3. Accurate quantum-chemical calculations: The use of Gaussian-type geminal functions in the treatment of electron correlation.

Author

Persson, B. Joakim and Taylor, Peter R.

Subjects
*QUANTUM chemistry, *ELECTRONS, *BASIS sets (Quantum mechanics)
Abstract

We investigate augmenting conventional Gaussian-type one-electron orbital basis sets with two-electron functions that have a Gaussian dependence on the interelectronic distance. We observe substantial improvements in calculated correlation energies for helium and neon atoms and for the water molecule. A feature of our approach is that there is no nonlinear optimization of the two-electron basis function parameters at all. © 1996 American Institute of Physics. [ABSTRACT FROM AUTHOR]

Published
1996
Full Text
View/download PDF

4. Pulsed laser evaporation of boron/carbon pellets: Infrared spectra and quantum chemical structures and frequencies for BC2.

Author

Martin, Jan M. L., Taylor, Peter R., Yustein, Jason T., Burkholder, Thomas R., and Andrews, Lester

Subjects
*BORON, *CARBON, *QUANTUM chemistry, *LASER beams
Abstract

Pulsed laser evaporation of pellets pressed from boron and graphite powder gave a new 1:4 doublet at 1232.5 and 1194.6 cm-1 in addition to the carbon cluster absorptions reported previously. The 1232.5 cm-1 band dominated boron-10 experiments. The new bands increased as carbon cluster bands decreased with increasing B/C ratio in the pellet and with increasing laser power. Augmented coupled cluster and full-valence complete active space SCF (CASSCF) calculations predict the global minimum BC2 structure to be an asymmetric triangle: however, the vibrationally averaged structure will be an isosceles triangle with a strong symmetric B–C2 stretching frequency near 1200 cm-1. The calculated boron-10/boron-11 frequency ratio (1.0323) is in excellent agreement with the observed ratio (1.0317), and confirms assignment of the 1194.6 cm-1 band to the BC2 ring. Calculations predict linear BCC to be less stable by 6.2±2 kcal/mol and to absorb in the 2000–2050 cm-1 range: the barrier towards rearrangement to the cyclic structure is very low (1.1 kcal/mol). Linear BCC was not detected in these experiments. Computed energetics explain why BC2 is abundant in B/C experiments, but absent in B+C2H2 experiments. [ABSTRACT FROM AUTHOR]

Published
1993
Full Text
View/download PDF

5. Behavior of the hartree-fock energy at short internuclear distances.

Author

Gilka, Natalie, Solovej, Jan Philip, and Taylor, Peter R.

Subjects
HARTREE-Fock approximation, THOMAS-Fermi theory, NUCLEAR charge, NUMERICAL analysis, PARTICLES (Nuclear physics), QUANTUM chemistry, FORCE & energy
Abstract

There are well-established mathematical relationships for the energy of a diatomic molecule (the exact energy, but also both the Hartree-Fock and Thomas-Fermi energies) in the limit of large nuclear charge of the atoms and small internuclear distances. We present calculated energies for a number of homonuclear diatomic molecules at short internuclear distances for numerical comparison with these established relationships. Intriguingly, they hold in practice for relatively small nuclear charges and for relatively long internuclear distances. © 2011 Wiley Periodicals, Inc. Int J Quantum Chem 111:3324-3328, 2011 [ABSTRACT FROM AUTHOR]

Published
2011
Full Text
View/download PDF

6. On the electronic structure of small cyclic carbon clusters

Author

Yousaf, Kazim E. and Taylor, Peter R.

Subjects
*ELECTRONIC structure, *CARBON, *QUANTUM chemistry, *SYMMETRY (Biology)
Abstract

Abstract: We present the results of correlated calculations on a variety of small carbon rings. Equilibrium structures and vibrational frequencies are calculated and transition states connecting symmetry-equivalent minima are considered in detail. We show that neither single-reference coupled-cluster nor multiconfigurational self-consistent field methods (even after perturbational inclusion of dynamical correlation effects) give qualitatively correct potential surfaces in the vicinity of the minima, suggesting that there is little recourse for these systems other than a multireference coupled-cluster treatment. Density-functional theory using the B3LYP functional produces results broadly in agreement with single-reference coupled-cluster methods and is thus no more reliable, but considerably more economical. [Copyright &y& Elsevier]

Published
2008
Full Text
View/download PDF

7. Lossless compression of wave function information using matrix factorization: A 'gzip' for quantum chemistry.

Author

Taylor, Peter R.

Subjects
*LOSSLESS data compression, *WAVE functions, *FACTORIZATION, *MATRICES (Mathematics), *QUANTUM chemistry, *CHEMICAL decomposition, *APPROXIMATION theory
Abstract

We propose the use of the singular value decomposition to decrease the storage required for wave function information. The specific case considered is determinantal full configuration interaction, but the same technique is readily applicable to truncated configuration interaction and coupled-cluster calculations of various types; as we discuss this is a reformulation of approximate methods that have been in use for some time, but our approach eliminates those approximations. Numerical examples support the contention that considerable compression of the wave function is possible without significant loss of accuracy: as expected a considerable amount of the information contained in the full CI wave function is redundant. [ABSTRACT FROM AUTHOR]

Published
2013
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results