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arXiv · 1803.00776

Microhartree Precision in Density-Functional-Theory Calculations

Andris Gulans·Anton Kozhevnikov·Claudia Draxl
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Abstract

To address ultimate precision in density-functional-theory calculations we employ the full-potential linearized augmented planewave + local-orbital (LAPW+lo) method and justify its usage as a benchmark method. LAPW+lo and two completely unrelated numerical approaches, multi-resolution analysis (MRA) and linear combination of atomic orbitals, yield total energies of atoms with a mean deviation of 0.9~μHa and 0.2~μHa, respectively. Spectacular agreement with the MRA is reached also for total and atomization energies of the G2-1 set consisting of 55 molecules. With the example of $α$-iron we demonstrate the capability of LAPW+lo of reaching μHa/atom precision also for periodic systems, which allows also for distinction between numerical precision and the accuracy of a given functional.

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Andris Gulans, Anton Kozhevnikov, Claudia Draxl. 2018-03-02. Microhartree Precision in Density-Functional-Theory Calculations. https://doi.org/10.1103/physrevb.97.161105

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