Test of an integral approximation scheme based on semiorthogonalized orbitals in LCAO SCF MO CI calculations of naphthalene

✍ Scribed by Hiroshi Kashiwagi; Toshikazu Takada

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 358 KB
• Volume: 12
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.560120304

✦ Synopsis

Abstract

Ab initio LCAO SCF MO CI calculations of naphthalene are carried out with a minimal basis set to test an integral approximation scheme proposed in a previous paper. When 71.3 and 53.0% of the two‐electron integrals are neglected, the errors in the SCF total energy are only −0.0534 and −0.0006 a.u., respectively. In the latter case, the maximum absolute errors of the orbital energy and the gross AO population are 0.007 a.u. and 0.001, respectively. Even in the former case the errors of the excitation energies are less than 0.0004 a.u. Errors of oscillator strengths are also examined and are found to be tolerably small.