Analytical energy gradients for local second-order Moller-Plesset perturbation theory

被引:191
作者
El Azhary, A
Rauhut, G
Pulay, P
Werner, HJ
机构
[1] Univ Stuttgart, Inst Theoret Chem, D-70569 Stuttgart, Germany
[2] Univ Arkansas, Dept Chem & Biochem, Fayetteville, AR 72701 USA
关键词
D O I
10.1063/1.475955
中图分类号
O64 [物理化学(理论化学)、化学物理学];
学科分类号
070304 ; 081704 ;
摘要
Based on the orbital invariant formulation of Moller-Plesset (MP) perturbation theory, analytical energy gradients have been formulated and implemented for local second order MP (LMP2) calculations. The geometry-dependent truncation terms of the LMP2 energy have to be taken into account. This leads to a set of coupled-perturbed localization (CPL) equations which must be solved together with the coupled-perturbed Hartree-Fock (CPHF) equations. In analogy to the conventional non-local theory, the repeated solution of these equations for each degree of freedom can be avoided by using the z-vector method of Handy and Schaefer. Explicit equations are presented for the Pipek-Mezey localization. Test calculations on smaller organic molecules demonstrate that the local approximations introduce only minor changes of computed equilibrium structures. (C) 1998 American Institute of Physics.
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页码:5185 / 5193
页数:9
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