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Evaluation of molecular integrals over Gaussian basis functions

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TLDR
This method is computationally simple and numerically well behaved, and has been incorporated into a new molecular SCF program HONDO, and preliminary tests indicate that it is competitive with existing methods especially for highly angularly dependent functions.
Abstract
This paper is concerned with the efficient computation of the ubiquitous electron repulsion integral in molecular quantum mechanics. Differences and similarities in organization of existing Gaussian integral programs are discussed, and a new strategy is developed. An analysis based on the theory of orthogonal polynomials yields a general formula for basis functions of arbitrarily high angular momentum. (ηiηj∥ηkηl) = Σα=1,nIx(uα) Iy(uα) I*z(uα) By computing a large block of integrals concurrently, the same I factors may be used for many different integrals. This method is computationally simple and numerically well behaved. It has been incorporated into a new molecular SCF program HONDO. Preliminary tests indicate that it is competitive with existing methods especially for highly angularly dependent functions.

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General atomic and molecular electronic structure system

TL;DR: A description of the ab initio quantum chemistry package GAMESS, which can be treated with wave functions ranging from the simplest closed‐shell case up to a general MCSCF case, permitting calculations at the necessary level of sophistication.
Journal ArticleDOI

Electronic structure calculations on workstation computers: the program system turbomole

TL;DR: TURBOMOLE as discussed by the authors is a program system for SCF that takes full advantage of all discrete point group symmetries and has only modest I/O and background storage requirements.
Journal ArticleDOI

Atomic charges derived from semiempirical methods

TL;DR: In this article, it is demonstrated that semi-empirical methods give electrostatic potential (ESP) derived atomic point charges that are in reasonable agreement with ab initio ESP charges.
Journal ArticleDOI

Molden: a pre- and post-processing program for molecular and electronic structures.

TL;DR: Molden is a software package for pre- and postprocessing of computational chemistry program data that features different options to display MOLecular electronic DENsity, each focusing on a different structural aspect: molecular orbitals, electron density, molecular minus atomic density and the Laplacian of the electron density.
Journal ArticleDOI

Advances in methods and algorithms in a modern quantum chemistry program package

TL;DR: Specific developments discussed include fast methods for density functional theory calculations, linear scaling evaluation of energies, NMR chemical shifts and electric properties, fast auxiliary basis function methods for correlated energies and gradients, equation-of-motion coupled cluster methods for ground and excited states, geminal wavefunctions, embedding methods and techniques for exploring potential energy surfaces.
References
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Book

Orthogonal polynomials

Gábor Szegő
Journal ArticleDOI

Electronic Wave Functions. I. A General Method of Calculation for the Stationary States of Any Molecular System

TL;DR: In this paper, it was shown that the only obstacle to the evaluation of wave functions of any required degree of accuracy is the labour of computation, and that all necessary integrals can be explicitly evaluated.
Journal ArticleDOI

Coulombic potential energy integrals and approximations

TL;DR: Theorems are derived which establish a method of approximating two‐particle Coulombic potential energy integrals, [φa(1) r12−1 |φb(2)], in terms of approximate charge densities φa′ and φb′, and a simple method of optimizing charge density approximations such that δ is minimized is derived.
Journal ArticleDOI

General contraction of Gaussian atomic orbitals: Core, valence, polarization, and diffuse basis sets; Molecular integral evaluation

TL;DR: The basis is compared with standard methods in current use and is shown to be superior in terms of energy lowering obtained per additional basis function beyond a minimal number.
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