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Related papers: Compact Formulae for Three-Center Nuclear Attracti…

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Three-centre nuclear attraction integrals, which arise in density functional and \textit{ab initio} calculations, are one of the most time-consuming computations involved in molecular electronic structure calculations. Even for relatively…

Numerical Analysis · Mathematics 2024-12-20 Jordan Lovrod , Hassan Safouhi

A program for molecular calculations with B functions is reported and its performance is analyzed. All the one- and two-center integrals, and the three-center nuclear attraction integrals are computed by direct procedures, using previously…

Chemical Physics · Physics 2016-02-19 E. O. Steinborn , H. H. H. Homeier , I. Ema , R. Lopez , G. Ramirez

Three-center nuclear attraction integrals with Slater type orbitals (STOs) appearing in the Hartree-Fock-Roothaan (HFR) equations for molecules are evaluated using one-range addition theorems of STOs obtained from the use of complete…

Mathematical Physics · Physics 2013-02-12 Israfil I. Guseinov , Nimet Zaim , Nursen Seckin Goorgun

Various properties of the general two-center two-electron integral over the explicitly correlated exponential function are analyzed for the potential use in high precision calculations for diatomic molecules. A compact one dimensional…

Chemical Physics · Physics 2015-06-11 Krzysztof Pachucki

An alternative methodology to evaluate two-electron-repulsion integrals based on numerical approximation is proposed. Computational chemistry has branched into two major fields with methodologies based on quantum mechanics and classical…

Chemical Physics · Physics 2016-09-22 Pedro E. M. Lopes

The series expansion formulae are established for the one- and two-center charge densities over complete orthonormal sets of exponential type orbitals introduced by the author. Three-center overlap integrals of appearing in these relations…

Chemical Physics · Physics 2009-02-04 I. I. Guseinov

The Slater orbitals are the natural basis functions in quantum molecular calculations. Three-center repulsion Coulomb-exchange integrals over Slater orbitals are evaluated analytically with arbitrary orbital exponents, first for linear…

Mathematical Physics · Physics 2012-09-18 Telhat Özdogan , Maria Belen Ruiz

In a recent paper Ozdogan (Z. Naturforsch, 59a(2004)743) published formulas for evaluating the two-center overlap and nuclear attraction integrals over integer and noninteger Slater type orbitals. The purpose of this article is to point out…

Chemical Physics · Physics 2007-05-23 I. I. Guseinov

The comments of Guseinov on our paper (T. Ozdogan, S. Gumus and M. Kara, J. Math. Chem., 33 (2003) 181) are critically analyzed. Contrary to his comments, it is proved that the expansion formula for the product of two normalized associated…

Mathematical Physics · Physics 2007-05-23 Telhat Ozdogan

The new combined formulas have been established for the complex and real rotation-angular functions arising in the evaluation of two-center overlap integrals over arbitrary atomic orbitals in molecular coordinate system. These formulas can…

Chemical Physics · Physics 2013-02-12 I. I. Guseinov

In this paper methods for calculations of multi-center integrals of squared Coulomb potentials and Slater-type orbitals (STO) are derived. These integrals are necessary for accurate lower bounds to energy levels of molecular systems. All…

Chemical Physics · Physics 2022-02-10 Sohei Ashida

The two-center two-electron Coulomb and hybrid integrals arising in relativistic and nonrelativistic ab-initio calculations of molecules are evaluated over the non-integer Slater-type orbitals via ellipsoidal coordinates. These integrals…

Quantum Physics · Physics 2014-05-22 Ali Bağcı , Philip E. Hoggan

A practical high-accuracy relativistic method of atomic structure calculations for univalent atoms is presented. The method is rooted in the coupled-cluster formalism and includes non-perturbative treatment of single and double excitations…

Atomic Physics · Physics 2009-11-11 Sergey G. Porsev , Andrei Derevianko

The computational cost of ab initio nuclear structure calculations is rendered particularly acute by the presence of (at least) three-nucleon interactions. This feature becomes especially critical now that many-body methods aim at extending…

We demonstrate a computational scheme which drastically decreases the required time to get theoretical predictions based on chiral two- and three-nucleon forces for observables in three-nucleon continuum. For a three-nucleon force…

Nuclear Theory · Physics 2021-08-04 H. Witała , J. Golak , R. Skibiński

We present a fast algorithm to calculate Coulomb/exchange integrals of prolate spheroidal electronic orbitals, which are the exact solutions of the single-electron, two-center Schr\"odinger equation for diatomic molecules. Our approach…

Quantum Physics · Physics 2012-08-01 Christian B. Mendl

Explicitly-correlated F12 methods are becoming the first choice for high-accuracy molecular orbital calculations, and can often achieve chemical accuracy with relatively small gaussian basis sets. In most calculations, the many three- and…

Chemical Physics · Physics 2016-05-25 Giuseppe M. J. Barca , Pierre-François Loos , Peter M. W. Gill

By using Poisson's summation formula, we calculate periodic integrals over Gaussian basis functions by partitioning the lattice summations between the real and reciprocal space, where both sums converge exponentially fast with a large…

Strongly Correlated Electrons · Physics 2021-04-06 Sandeep Sharma , Gregory Beylkin

In this paper we consider calculation of two-centre exchange integrals over Slater-type orbitals (STOs). We apply the Neumann expansion of the Coulomb interaction potential and consider calculation of all basic quantities which appear in…

Quantum Physics · Physics 2016-11-04 Michał Lesiuk , Robert Moszynski

This work describes the fully analytical method for calculation of the molecular integrals over Slater-type orbitals with non-integer principal quantum numbers. These integrals are expressed through relativistic molecular auxiliary…

Chemical Physics · Physics 2020-04-08 A. Bagci , P. E. Hoggan
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