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arXiv · 2110.06638

Variational Dirac-Coulomb explicitly correlated computations for atoms and molecules

Péter Jeszenszki·Dávid Ferenc·Edit Mátyus
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Abstract

The Dirac-Coulomb equation with positive-energy projection is solved using explicitly correlated Gaussian functions. The algorithm and computational procedure aims for a parts-per-billion convergence of the energy to provide a starting point for further comparison and further developments in relation with high-resolution atomic and molecular spectroscopy. Besides a detailed discussion of the implementation of the fundamental spinor structure, permutation and point-group symmetries, various options for the positive-energy projection procedure are presented. The no-pair Dirac-Coulomb energy converged to a parts-per-billion precision is compared with perturbative results for atomic and molecular systems with small nuclear charge numbers. The subsequent paper [Paper II: D. Ferenc, P. Jeszenszki, and E. M\'atyus (2022)] describes the implementation of the Breit interaction in this framework.

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Péter Jeszenszki, Dávid Ferenc, Edit Mátyus. 2021-10-13. Variational Dirac-Coulomb explicitly correlated computations for atoms and molecules. https://doi.org/10.1063/5.0075096

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