Journal ArticleDOI
Natural population analysis
TLDR
In this paper, a method of "natural population analysis" was developed to calculate atomic charges and orbital populations of molecular wave functions in general atomic orbital basis sets, which seems to exhibit improved numerical stability and to better describe the electron distribution in compounds of high ionic character.Abstract:
A method of ‘‘natural population analysis’’ has been developed to calculate atomic charges and orbital populations of molecular wave functions in general atomic orbital basis sets. The natural analysis is an alternative to conventional Mulliken population analysis, and seems to exhibit improved numerical stability and to better describe the electron distribution in compounds of high ionic character, such as those containing metal atoms. We calculated ab initio SCF‐MO wave functions for compounds of type CH3X and LiX (X=F, OH, NH2, CH3, BH2, BeH, Li, H) in a variety of basis sets to illustrate the generality of the method, and to compare the natural populations with results of Mulliken analysis, density integration, and empirical measures of ionic character. Natural populations are found to give a satisfactory description of these molecules, providing a unified treatment of covalent and extreme ionic limits at modest computational cost.read more
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Chemistry with ADF
G. te Velde,F.M. Bickelhaupt,Evert Jan Baerends,C. Fonseca Guerra,S. J. A. van Gisbergen,J.G. Snijders,T. Ziegler +6 more
TL;DR: The “Activation‐strain TS interaction” (ATS) model of chemical reactivity is reviewed as a conceptual framework for understanding how activation barriers of various types of reaction mechanisms arise and how they may be controlled, for example, in organic chemistry or homogeneous catalysis.
Journal ArticleDOI
Advances in methods and algorithms in a modern quantum chemistry program package
Yihan Shao,Laszlo Fusti Molnar,Yousung Jung,Jörg Kussmann,Christian Ochsenfeld,Shawn T. Brown,Andrew T. B. Gilbert,Lyudmila V. Slipchenko,Sergey V. Levchenko,Darragh P. O’Neill,Robert A. DiStasio,Rohini C. Lochan,Tao Wang,Gregory J. O. Beran,Nicholas A. Besley,John M. Herbert,Ching Yeh Lin,Troy Van Voorhis,Siu Hung Chien,Alexander J. Sodt,Ryan P. Steele,Vitaly A. Rassolov,Paul E. Maslen,Prakashan P. Korambath,Ross D. Adamson,Brian Austin,Jon Baker,Edward F. C. Byrd,Holger Dachsel,Robert J. Doerksen,Andreas Dreuw,Barry D. Dunietz,Anthony D. Dutoi,Thomas R. Furlani,Steven R. Gwaltney,Andreas Heyden,So Hirata,Chao-Ping Hsu,Gary S. Kedziora,Rustam Z. Khalliulin,Phil Klunzinger,Aaron M. Lee,Michael S. Lee,WanZhen Liang,Itay Lotan,Nikhil Nair,Baron Peters,Emil Proynov,Piotr A. Pieniazek,Young Min Rhee,Jim Ritchie,Edina Rosta,C. David Sherrill,Andrew C. Simmonett,Joseph E. Subotnik,H. Lee Woodcock,Weimin Zhang,Alexis T. Bell,Arup K. Chakraborty,Daniel M. Chipman,Frerich J. Keil,Arieh Warshel,Warren J. Hehre,Henry F. Schaefer,Jing Kong,Anna I. Krylov,Peter Gill,Martin Head-Gordon,Martin Head-Gordon +68 more
TL;DR: Specific developments discussed include fast methods for density functional theory calculations, linear scaling evaluation of energies, NMR chemical shifts and electric properties, fast auxiliary basis function methods for correlated energies and gradients, equation-of-motion coupled cluster methods for ground and excited states, geminal wavefunctions, embedding methods and techniques for exploring potential energy surfaces.
Journal ArticleDOI
Advances in molecular quantum chemistry contained in the Q-Chem 4 program package
Yihan Shao,Zhengting Gan,Evgeny Epifanovsky,Andrew T. B. Gilbert,Michael Wormit,Joerg Kussmann,Adrian W. Lange,Andrew Behn,Jia Deng,Xintian Feng,Debashree Ghosh,Matthew Goldey,Paul R. Horn,Leif D. Jacobson,Ilya Kaliman,Rustam Z. Khaliullin,Tomasz Kuś,Arie Landau,Jie Liu,Emil Proynov,Young Min Rhee,Ryan M. Richard,Mary A. Rohrdanz,Ryan P. Steele,Eric J. Sundstrom,H. Lee Woodcock,Paul M. Zimmerman,Dmitry Zuev,Ben Albrecht,Ethan Alguire,Brian J. Austin,Gregory J. O. Beran,Yves A. Bernard,Eric J. Berquist,Kai Brandhorst,Ksenia B. Bravaya,Shawn T. Brown,David Casanova,Chun-Min Chang,Yunqing Chen,Siu Hung Chien,Kristina D. Closser,Deborah L. Crittenden,Michael Diedenhofen,Robert A. DiStasio,Hainam Do,Anthony D. Dutoi,Richard G. Edgar,Shervin Fatehi,Laszlo Fusti-Molnar,An Ghysels,Anna Golubeva-Zadorozhnaya,Joseph Gomes,Magnus W. D. Hanson-Heine,Philipp H. P. Harbach,Andreas W. Hauser,Edward G. Hohenstein,Zachary C. Holden,Thomas-C. Jagau,Hyunjun Ji,Benjamin Kaduk,Kirill Khistyaev,Jae-Hoon Kim,Jihan Kim,Rollin A. King,Phil Klunzinger,Dmytro Kosenkov,Tim Kowalczyk,Caroline M. Krauter,Ka Un Lao,Adèle D. Laurent,Keith V. Lawler,Sergey V. Levchenko,Ching Yeh Lin,Fenglai Liu,Ester Livshits,Rohini C. Lochan,Arne Luenser,Prashant Uday Manohar,Samuel F. Manzer,Shan-Ping Mao,Narbe Mardirossian,Aleksandr V. Marenich,Simon A. Maurer,Nicholas J. Mayhall,Eric Neuscamman,C. Melania Oana,Roberto Olivares-Amaya,Darragh P. O’Neill,John Parkhill,Trilisa M. Perrine,Roberto Peverati,Alexander Prociuk,Dirk R. Rehn,Edina Rosta,Nicholas J. Russ,Shaama Mallikarjun Sharada,Sandeep Sharma,David W. Small,Alexander J. Sodt,Tamar Stein,David Stück,Yu-Chuan Su,Alex J. W. Thom,Takashi Tsuchimochi,Vitalii Vanovschi,Leslie Vogt,Oleg A. Vydrov,Tao Wang,Mark A. Watson,Jan Wenzel,Alec F. White,Christopher F. Williams,Jun Yang,Sina Yeganeh,Shane R. Yost,Zhi-Qiang You,Igor Ying Zhang,Xing Zhang,Yan Zhao,Bernard R. Brooks,Garnet Kin-Lic Chan,Daniel M. Chipman,Christopher J. Cramer,William A. Goddard,Mark S. Gordon,Warren J. Hehre,Andreas Klamt,Henry F. Schaefer,Michael W. Schmidt,C. David Sherrill,Donald G. Truhlar,Arieh Warshel,Xin Xu,Alán Aspuru-Guzik,Roi Baer,Alexis T. Bell,Nicholas A. Besley,Jeng-Da Chai,Andreas Dreuw,Barry D. Dunietz,Thomas R. Furlani,Steven R. Gwaltney,Chao-Ping Hsu,Yousung Jung,Jing Kong,Daniel S. Lambrecht,WanZhen Liang,Christian Ochsenfeld,Vitaly A. Rassolov,Lyudmila V. Slipchenko,Joseph E. Subotnik,Troy Van Voorhis,John M. Herbert,Anna I. Krylov,Peter Gill,Martin Head-Gordon +156 more
TL;DR: A summary of the technical advances that are incorporated in the fourth major release of the Q-Chem quantum chemistry program is provided in this paper, covering approximately the last seven years, including developments in density functional theory and algorithms, nuclear magnetic resonance (NMR) property evaluation, coupled cluster and perturbation theories, methods for electronically excited and open-shell species, tools for treating extended environments, algorithms for walking on potential surfaces, analysis tools, energy and electron transfer modelling, parallel computing capabilities, and graphical user interfaces.
RESEARCH ARTICLE Advances in molecular quantum chemistry contained in the Q-Chem 4 program package
Yihan Shao,Zhengting Gan,Evgeny Epifanovsky,Michael Wormit,Joerg Kussmann,Adrian W. Lange,Andrew Behn,Jia Deng,Xintian Feng,Debashree Ghosh,Matthew Goldey,Paul R. Horn,L eif,J ie Liu,I. Proynov,Ryan M. Richard,Mary A. Rohrdanz,Ryan P. Steele,Eric J. Sundstrom,H. Lee Woodcock,Dmitry Zuev,Ben Albrecht,Ethan Alguire,Brian Austin,Gregory J. O. Beran,Yves A. Bernard,Eric Berquist,Kai Brandhorst,Ksenia B. Bravaya,Shawn T. Brown,David Casanova,Chun-Min Chang,Yunqing Chen,Siu Hung Chien,Kristina D. Closser,Deborah L. Crittenden,Hainam Do,Anthony D. Dutoi,Richard G. Edgar r,Laszlo Fusti-Molnar,Anna Golubeva-Zadorozhnaya,Joseph Gomes,Andreas W. Hauser,Edward G. Hohenstein,Zachary C. Holden +44 more
TL;DR: Detailed benchmarks of the comparative accuracy of modern density functionals for bonded and non-bonded interactions, tests of attenuated second order Møller–Plesset methods for intermolecular interactions, and tests of the accuracy of implicit solvation models are provided.
Journal ArticleDOI
Analysis of the geometry of the hydroxymethyl radical by the “different hybrids for different spins” natural bond orbital procedure
John E. Carpenter,Frank Weinhold +1 more
TL;DR: In this paper, the electronic structure of the radical CH 2 OH was analyzed via the "different hybrids for different spins" natural bond orbital (DHDS NBO) procedure, which finds separate Lewis structures for each of the spin systems.
References
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Journal ArticleDOI
Electronic Population Analysis on LCAO–MO Molecular Wave Functions. I
TL;DR: In this paper, an analysis in quantitative form is given in terms of breakdowns of the electronic population into partial and total ''gross atomic populations'' and ''overlap populations'' for molecules.
Journal ArticleDOI
Gaussian Basis Functions for Use in Molecular Calculations. III. Contraction of (10s6p) Atomic Basis Sets for the First‐Row Atoms
TL;DR: In this paper, the effects of contraction on the energies and one-electron properties of the water and nitrogen molecules were investigated, and the authors obtained principles which can be used to predict optimal contraction schemes for other systems without the necessity of such exhaustive calculations.
Journal ArticleDOI
Self‐Consistent Molecular‐Orbital Methods. I. Use of Gaussian Expansions of Slater‐Type Atomic Orbitals
TL;DR: In this article, a least square representation of Slater-type atomic orbitals as a sum of Gaussian-type orbitals is presented, where common Gaussian exponents are shared between Slater−type 2s and 2p functions.
Journal ArticleDOI
Quantum Theory of Many-Particle Systems. I. Physical Interpretations by Means of Density Matrices, Natural Spin-Orbitals, and Convergence Problems in the Method of Configurational Interaction
TL;DR: In this article, the authors define a set of generalized density matrices for the Hermitean density matrix of order $k, which is further antisymmetric in each set of these indices.
Journal ArticleDOI
On the Non‐Orthogonality Problem Connected with the Use of Atomic Wave Functions in the Theory of Molecules and Crystals
TL;DR: In this article, the authors show that the overlap integrals are of essential importance in molecules and in crystals, instead of being negligible, and the problem is simply solved by considering the orthonormalized functions [open phi]μ, given by (21), as the real atomic orbitals.