Removal of singularities in the numerical integrals for an STO basis set

✍ Scribed by P. N. Careless; D. Hyatt; L. Stanton

• Publisher: John Wiley and Sons
• Year: 1977
• Tongue: English
• Weight: 413 KB
• Volume: 12
• Category: Article
• ISSN: 0020-7608
• DOI: 10.1002/qua.560120315

✦ Synopsis

Abstract

Advantages and difficulties of numerical integration in relation to a transcorrelated solution of the molecular Schrödinger equation are discussed. Because singularities in the two‐electron integrals can be completely removed in a transcorrelated calculation, the major difficulty remaining to be resolved is that of singularities in the one‐electron integrals. A general method of treating this problem is given which involves the derivation of some new polycentric expansion functions which are everywhere finite under the one‐electron part of the Hailtonian. The important improvements obtained are illustrated by some calculations on LiH.