New recurrence relations for the rapid evaluation of electron repulsion integrals based on the accompanying coordinate expansion formula.
We present an algorithm for the rapid computation of electron repulsion integrals (ERIs) over Gaussian basis functions based on the accompanying coordinate expansion (ACE) formula. The present algorithm uses equations termed angular momentum reduced expressions and introduces two types of recurrence relations to ACE formulas. Numerical efficiencies are assessed for (p pmid R:p p) and (sp spmid R:sp sp) ERIs by using the floating-point operation count. The algorithm is suitable for calculating ERIs for the same exponents but different angular momentum functions, such as L shells and derivatives of ERIs. The present algorithm is also capable of calculating ERIs with highly contracted Gaussian basis functions.
Kobayashi
Masato
M
Department of Chemistry, School of Science and Engineering, Waseda University, Tokyo 169-8555, Japan.
Nakai
Hiromi
H