Journal ArticleDOI
Anharmonic force fields from analytic second derivatives: Method and application to methyl bromide
Winfried Schneider,Walter Thiel +1 more
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This article is published in Chemical Physics Letters.The article was published on 1989-05-12. It has received 324 citations till now. The article focuses on the topics: Anharmonicity & Coupling constant.read more
Citations
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Anharmonic vibrational properties by a fully automated second-order perturbative approach
TL;DR: This paper describes the implementation of a fully automated code for the building of anharmonic force constants and their use in a second-order perturbative evaluation of vibrorotational parameters.
Journal ArticleDOI
Vibrational zero-point energies and thermodynamic functions beyond the harmonic approximation
TL;DR: This paper compares harmonic and anharmonic zero-point energies and thermodynamic functions for a number of molecules of small and medium size using the Becke three parameter Lee-Yang-Parr functional, medium size basis sets, and, when needed, proper treatment of internal rotations.
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Frequency and zero-point vibrational energy scale factors for double-hybrid density functionals (and other selected methods): can anharmonic force fields be avoided?
TL;DR: Uniform frequency scaling factors for true anharmonic fundamentals and ZPVEs obtained from quartic force fields are obtained and simple uniform scaling is clearly inadequate.
Journal ArticleDOI
Coupled-cluster techniques for computational chemistry: The CFOUR program package
Devin A. Matthews,Lan Cheng,Michael E. Harding,Filippo Lipparini,Stella Stopkowicz,Thomas-C. Jagau,Péter G. Szalay,Jürgen Gauss,John F. Stanton +8 more
TL;DR: An up-to-date overview of the CFOUR program system and its well-known capabilities for high-level coupled-cluster theory and its application to molecular properties is given.
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Analytic CCSD(T) second derivatives
Jürgen Gauss,John F. Stanton +1 more
TL;DR: In this paper, a general-purpose implementation of analytic CCSD(T) second derivatives is presented, which is demonstrated by calculations of vibration-rotation interaction constants for the astrophysically important molecule cyclopropenylidene (C3H2).
References
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Journal ArticleDOI
Self—Consistent Molecular Orbital Methods. XII. Further Extensions of Gaussian—Type Basis Sets for Use in Molecular Orbital Studies of Organic Molecules
TL;DR: In this article, two extended basis sets (termed 5-31G and 6 -31G) consisting of atomic orbitals expressed as fixed linear combinations of Gaussian functions are presented for the first row atoms carbon to fluorine.
Journal ArticleDOI
The influence of polarization functions on molecular orbital hydrogenation energies
P. C. Hariharan,John A. Pople +1 more
TL;DR: In this paper, a split-valence extended gaussian basis set was used to obtain the LCAO-MO-SCF energies of closed shell species with two non-hydrogen atoms.
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Ab initio effective core potentials for molecular calculations. Potentials for main group elements Na to Bi
Willard R. Wadt,P. Jeffrey Hay +1 more
TL;DR: In this article, a consistent set of ab initio effective core potentials (ECP) has been generated for the main group elements from Na to Bi using the procedure originally developed by Kahn.
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Anharmonic force constant calculations
A.R. Hoy,Ian Mills,G. Strey +2 more
TL;DR: The relationship of the anharmonic force constants in curvilinear internal coordinates to the observed vibration-rotation spectrum of a molecule is reviewed in this paper, where a simplified method of setting up the required non-linear coordinate transformations is described: this makes use of an L tensor, which is a straightforward generalization of the L matrix used in the customary description of harmonic force constant calculations.
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The elimination of singularities in derivative calculations
TL;DR: In this article, the second derivatives of the electronic energy of a molecule are evaluated for two methods which include electron correlation effects - configuration interaction and perturbation theory, and numerically stable procedures can be devised using the fact that the energy is invariant to certain orbital rotations amongst occupied and amongst virtual orbitals.