Frank E. Harris

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Reliable, tractable computational characterization of warm dense matter is a challenging task because of the wide range of important aggregation states and effective interactions involved. Contemporary best practice is to do ab initio molecular dynamics on the ion constituents with the forces from the electronic population provided by density functional(More)
V. V. Karasiev,1,2,* R. S. Jones,3 S. B. Trickey,2,† and Frank E. Harris2,4 1Centro de Química, Instituto Venezolano de Investigaciones Científicas, Apartado 21827, Caracas 1020-A, Venezuela 2Quantum Theory Project, Departments of Physics and of Chemistry, University of Florida, Gainesville, Florida 32611, USA 3Department of Physics, Loyola College in(More)
The subject paper by H. Safouhi (J Mol Model 12:213-220, 2006) presents a scheme based on a nonlinear convergence acceleration transformation for the numerical evaluation of two-center overlap integrals of Slater-type orbitals. In this comment we argue that there is no reason to adopt such an approach, as well-known methods for these integrals are(More)
Expressions for integrals involving general Gaussian (s, p, d, [ellipsis (horizontal)]) basis Bloch functions are presented. Applying the Poisson transformation and the Ewald-type partitioning scheme, all lattice sums appearing in these expressions lead to fast convergence in both direct and Fourier spaces. Numerical results produced for selected test cases(More)
Many-electron systems confined at substantial finite temperatures and densities present a major challenge to density functional theory. In particular, there is comparatively little systematic knowledge about the behavior of free-energy density functionals for temperatures and pressures of interest, for example, in the study of warm dense matter (WDM). As(More)
Restricted Hartree-Fock computations are reported for a methyl isocyanide polymer (repeating unit -C═N-CH3), whose most stable conformation is expected to be a helical chain. The computations used a standard contracted Gaussian orbital set at the computational levels STO-3G, 3-21G, 6-31G, and 6-31G**, and studies were made for two line-group configurations(More)
V.V. Karasiev, R.S. Jones, S.B. Trickey and Frank E. Harris Centro de Química, Instituto Venezolano de Investigaciones Científicas IVIC, Apartado 21827, Caracas 1020-A, Venezuela and Quantum Theory Project, Departments of Physics and of Chemistry, University of Florida Gainesville, FL 32611, USA; Dept. of Physics, Loyola College in Maryland 4501 N. Charles(More)