ISSN:
0020-7608
Schlagwort(e):
Boys function
;
molecular integrals over Gaussian functions
;
computation of Boys function
;
error function erf(x)
;
electron repulsion integrals
;
Chemistry
;
Theoretical, Physical and Computational Chemistry
Quelle:
Wiley InterScience Backfile Collection 1832-2000
Thema:
Chemie und Pharmazie
Notizen:
We propose a new expansion for the Boys function ∫01t2jexp(-r2t2) dt appearing in the calculation of molecular two-electron matrix elements if Gaussian basis sets are employed. This expansion involves a power series involving the terms Ci, j(τ) (r2-R2)i multiplied by exp(-τr2), where τ is an optimized parameter τ∊[0, 1]. The performances of the introduced expansion are discussed and illustrated by some numerical experiments. It appears that the proposed expansion is considerably shorter than the customary Taylor series, which in turn is the special case for τ=0. This is of some importance, particularly for higher j values. Further, the proposed expansion enables a single expression for calculating erf(x) for the whole range of variable x. The recursive relations for the expansion coefficients are derived and the truncation errors are estimated. A new method for calculating the Boys function by means of asymptotic series is represented too. © 1998 John Wiley & Sons, Inc. Int J Quant Chem 68: 305-315, 1998
Zusätzliches Material:
5 Tab.
Materialart:
Digitale Medien
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