Journal
JOURNAL OF CHEMICAL PHYSICS
Volume 129, Issue 6, Pages -Publisher
AMER INST PHYSICS
DOI: 10.1063/1.2938371
Keywords
-
Funding
- The Laboratoire de Chimie et Physique Quantiques is Unite Mixte de Recherche [UMR 5626]
Ask authors/readers for more resources
The present paper presents a revised version of a size-consistency correction to the multireference configuration interaction techniques previously proposed by Szalay [J. Phys. Chem. 100, 6288 (1996)]. The method assumes a complete active space reference space and separates the nonreference determinants in several classes according to their number of inactive holes and particles. The correction is formulated as a dressing of the diagonal energies of these determinants, which depends on their class, as originally proposed by Ruttink [J. Chem. Phys. 94, 7212 (1991)]. The exclusion principle violating corrections are evaluated through a simple counting of the various excitation processes which remain possible on each class. The efficiency of the method has been tested on a series of multireference problems for which full configuration interaction results are available (OH(2) bond breaking, Be insertion in H(2), excited states of CH(2)). The dressing of a given state not only provides excellent results for this state but also provides accurate excited roots. The efficiency of state-specific dressings is dramatic. The adaptation of this proposal to difference-dedicated configuration interactions can be extremely fruitful, as illustrated in the calculation of the 1 (1)A(g)-1(1)B(u)(pi->pi*) transition energy of the trans-butadiene molecule. (C) 2008 American Institute of Physics.
Authors
I am an author on this paper
Click your name to claim this paper and add it to your profile.
Reviews
Recommended
No Data Available