Low-rank configuration interaction with orbital optimization - the LR SCF approach

• Orbital optimization has been included in the low-range (LR) CI approach to configuration interaction, It is shown to have a noticeable effect on the computed correlation energy when only a small number of single excitation operators are used to approximate the doubly excited part of the wavefunction. The importance of optimization decreases rapidly when the number of parameters describing the LR wavefunction is increased. Test calculations are performed for H2O (geometry optimization) and for the polarizability of F−. Optimization of the orbitals leads to improved convergence for all properties studied.

Subject headings

NATURVETENSKAP  -- Kemi (hsv//swe)

NATURAL SCIENCES  -- Chemical Sciences (hsv//eng)

Keyword

Chemistry

Kemi

Publication and Content Type

ref (subject category)

art (subject category)