Journal ArticleDOI
An efficient method for the evaluation of coupling coefficients in configuration interaction calculations
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TLDR
In this article, a new method for evaluating one-particle coupling coefficients in general configuration interaction calculation is presented, through repeated application and use of resolutions of the identity, two-, three-and four-body coupling coefficients and density matrices may be built in a simple and efficient way.About:
This article is published in Chemical Physics Letters.The article was published on 1988-04-22. It has received 2455 citations till now. The article focuses on the topics: Multireference configuration interaction & Configuration interaction.read more
Citations
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Journal ArticleDOI
An efficient internally contracted multiconfiguration–reference configuration interaction method
TL;DR: In this article, a new internally contracted direct multiconfiguration-reference configuration interaction (MRCI) method is described which allows the use of much larger reference spaces than any previous MRCI method.
Journal ArticleDOI
Molpro: a general-purpose quantum chemistry program package
TL;DR: Molpro (available at http://www.molpro.net) is a general-purpose quantum chemical program as discussed by the authors, which uses local approximations combined with explicit correlation treatments, highly accurate coupled-cluster calculations are now possible for molecules with up to approximately 100 atoms.
Journal ArticleDOI
Benchmark calculations with correlated molecular wave functions. IV. The classical barrier height of the H+H2→H2+H reaction
TL;DR: In this paper, the authors used correlation consistent Gaussian basis sets from double to sextuple zeta quality to estimate the barrier height of the H+H2 exchange reaction.
Book ChapterDOI
Chapter 41 – Advances in electronic structure theory: GAMESS a decade later
TL;DR: GAMESS as discussed by the authors is a suite of electronic structure and QM/MM methods (including open-and closed-shell Hartree-Fock which has been essentially ignored here) that can be run on virtually any computer, cluster, massively parallel system or for that matter a desktop Mac or PC.
Journal ArticleDOI
Energy‐adjusted pseudopotentials for the actinides. Parameter sets and test calculations for thorium and thorium monoxide
TL;DR: In this paper, nonrelativistic and quasirelativistic energy adjusted pseudopotentials, the latter augmented by spin-orbit operators, as well as optimized (12s11p10d8f)/ [8s7p6d4f]−Gaussian-type orbitals (GTO) valence basis sets for the actinide elements actinium through lawrencium, were presented.
References
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Journal ArticleDOI
A new determinant-based full configuration interaction method
TL;DR: In this article, instead of using configuration state functions as adopted by Siegbahn, the Slater determinants are used instead of formula tape, the one-electron coupling coefficients being easily generated as required.
Journal ArticleDOI
The self‐consistent electron pairs method for multiconfiguration reference state functions
TL;DR: In this paper, an efficient direct CI method which includes all singly and doubly substituted configurations with respect to an arbitrary multiconfiguration (MCSCF) reference function is described.
Journal ArticleDOI
Generalizations of the direct CI method based on the graphical unitary group approach. II. Single and double replacements from any set of reference configurations
TL;DR: In this paper, the coupling coefficients appearing in the direct CI formalism are factorized into a complicated internal part and a simple external part, which is then used for the unitary group formulation of the correlation problem.
Journal ArticleDOI
The direct CI method
V. R. Saunders,J.H. van Lenthe +1 more
TL;DR: A thorough analysis of the direct CI method as applied to the case of a general set of reference configurations coupled to all single and double substitutions is presented in this article, where a variety of procedures are presented together with rules to enable the selection of the most favorable under a given circumstance.
Journal ArticleDOI
A new direct CI method for large CI expansions in a small orbital space
TL;DR: In this article, a new direct CI method is presented, which is particularly suited for large CI expansions in a small orbital space, where only one-electron coupling coefficients are stored, leading to reduced elapsed times and storage requirements compared to earlier approaches.