One-electron properties using a CI method based on multiple Hartree–Fock solutions

A multi-reference configuration interaction (CI) method based on multiple Hartree–Fock (HF) solutions is applied to study the permanent dipole moment of the LiH, BH, FH, and H₂O systems with the minimal atomic basis. The LiH was also calculated with the double-zeta atomic basis. This method uses several HF solutions as references to expand the state functions. For each one of the systems studied, several HF solutions were obtained in the appropriate point and spin symmetry classes, i.e., ¹Σ⁺ and ¹A₁. With each of these solutions is generated a distinct basis of the same full CI space. The set of these bases is a system of generators of the full CI space and the multi-reference HF (MRHF) bases are built mixing configuration state functions (CSFs) originated from distinct HF solutions. © 2006 Wiley Periodicals, Inc. Int J Quantum Chem, 2006