A Gaussian quadrature formula for hypersingular integrals with second-order singularities is developed based on previous Gaussian quadrature formulae for Cauchy principal value integrals. The formula uses classical orthonormal polynomials, and the formula is then specialized to the case of Legendre
Calculation of Gaussian integrals using symbolic manipulation
โ Scribed by Paul Bracken; Rodney J. Bartlett
- Publisher
- John Wiley and Sons
- Year
- 1997
- Tongue
- English
- Weight
- 191 KB
- Volume
- 62
- Category
- Article
- ISSN
- 0020-7608
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โฆ Synopsis
The calculation of molecular integrals is extremely important for applications to such diverse areas as statistical mechanics and quantum chemistry. A careful derivation of a method for calculating primitive Gaussian integrals originally proposed by Obara and Saika is presented. The basic recursion relations for the two-and three-center overlap integrals is derived using a simple technique. Several new horizontal recursion relations are given. Finally, an innovative method for implementing these recursion relations is discussed. The recursion relations in this form are suited for programming using a symbolic manipulation language. There are several reasons why it is of interest to consider programming with symbolic manipulation. It has been found that it is possible to write algorithms that will generate values for Gaussian integrals for very large values of angular momentum automatically. Calculations can be done to arbitrary precision in Maple. Having these recursions programmed in Maple allows for the possibility of using the Maple programs to help in the writing of similar programs in other languages which are, numerically, much faster.
๐ SIMILAR VOLUMES
Symbolic calculation is applied to the evaluation of molecular integrals over Slater orbitals (STOs). A recurrence scheme is developed for some new auxiliary functions that facilitate this work. Closed expressions are developed independently for use in spot checks. A table of formulas for the indivi
In this paper we will consider some of the methods involved in carrying out density functional calculations within the framework of localised basis sets, specifically those of Gaussian type orbitals. Particular emphasis is placed on the methods used in the AIMPRO (Ab Initio Modelling PROgram) code,
The multicenter charge-density expansion coefficients [I. I. Guseinov, J Mol Struct (Theochem) 417, 117 (1997)] appearing in the molecular integrals with an arbitrary multielectron operator were calculated for extremely large quantum numbers of Slater-type orbitals (STOs). As an example, using compu
Using expansion formulas for the charge-density over Slater-type orbitals (STOs) obtained by the one of authors [I. I. Guseinov, J Mol Struct (Theochem) 1997, 417, 117] the multicenter molecular integrals with an arbitrary multielectron operator are expressed in terms of the overlap integrals with t