The orthogonality assumption in the Hartree–Fock approximation for 2pn3p configurations

Abstract

Hartree–Fock (HF) results for Na⁺ 2p⁵3p¹S and Ne⁺ 1s2p⁵3p²S are reported. In order for the SCF process to converge, additional orthogonality constraints to the corresponding 2p⁶ states had to be introduced. The resulting 2p functions were nodeless. Similar calculations were performed for O 2p³3p²P and Ne⁺ 2p⁴3p²P for which standard HF results were available. A comparison of the two methods indicates that, unlike the He 1s2s¹S case, the additional orthogonality constraint did not improve the total energy although it removed the extra node from the 2p function.