✦ LIBER ✦

Two-electron integral evaluation for uncontracted geometrical-type Gaussian functions

✍ Scribed by M. W. Wong; G. Corongiu; E. Clementi

Publisher: John Wiley and Sons
Year: 1991
Tongue: English
Weight: 524 KB
Volume: 12
Category: Article
ISSN: 0192-8651
DOI: 10.1002/jcc.540120211

No coin nor oath required. For personal study only.

✦ Synopsis

A new algorithm for efficient evaluation of two-electron repulsion integrals (ERIs) using uncontracted geometrical-type Gaussian basis functions is presented. Integrals are evaluated by the Habitz and Clementi method. The use of uncontracted geometrical basis sets allows grouping of basis functions into shells (s, sp, spd, or spdf) and processing of integrals in blocks (shell quartets). By utilizing information common to a block of integrals, this method achieves high efficiency. This technique has been incorporated into the KGNMOL molecular interaction program. Representative timings for a number of molecules with different basis sets are presented. The new code is found to be significantly faster than the previous program. For ERIs involving only s and p functions, the new algorithm is a factor of two faster than previously. The new program is also found to be competitive when compared with other standard molecular packages, such as HONDO-8 and Gaussian 86.

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