Equations providing the first and second derivatives of a configuration interaction (CI) energy with respect to an external parameter are provided. We assume no restriction on the form of the CI expansion built from molecular orbitals obtained in a multiconfiguration Hartree-Fock (MCHF) calculation. Also, the coupled perturbed multiconfiguration Hartree-Fock formalism is presented for a general MCHF wave function and provides the first order and second order changes of the molecular orbital expansion coefficients with respect to an external parameter.
|Number of pages||8|
|Journal||Journal of Chemical Physics|
|Publication status||Published - 1981|
ASJC Scopus subject areas
- Atomic and Molecular Physics, and Optics