A usual procedure to get a large fraction of the correlation energy consists in the evaluation of the second order perturbation contribution to the electronic energy by utilizing as zeroth order state a moderate size CI wave function (CIPSI algorithm). A scheme of calculation based on a hole‐particle formulation of the Hamiltonian, leading to a diagrammatic pattern quite similar to the one used for the one‐determinant case, is proposed and discussed.
Second order perturbation correction to CI energies by use of diagrammatic techniques: an improvement to the CIPSI algorithm
CIMIRAGLIA, Renzo
1985
Abstract
A usual procedure to get a large fraction of the correlation energy consists in the evaluation of the second order perturbation contribution to the electronic energy by utilizing as zeroth order state a moderate size CI wave function (CIPSI algorithm). A scheme of calculation based on a hole‐particle formulation of the Hamiltonian, leading to a diagrammatic pattern quite similar to the one used for the one‐determinant case, is proposed and discussed.File in questo prodotto:
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