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arXiv · 1801.03891

The role of non-spherical double counting in DFT+DMFT: total energy and structural optimization of pnictide superconductors

Oleg Kristanovski·Alexander Shick·Frank Lechermann·Alexander Lichtenstein
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Abstract

A simple scheme for avoiding non-spherical double counting in the combination of density func- tional theory with dynamical mean-field theory (DFT+DMFT)is developed. It is applied to total- energy calculations and structural optimization of the pnictide superconductor LaFeAsO. The results are compared to a recently proposed "exact" double-counting formulation. Both schemes bring the optimized Fe-As interatomic distance close to the experimental value. This resolves the long stand- ing controversy between DFT+DMFT and experiment for the structural optimization of LaFeAsO.

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Oleg Kristanovski, Alexander Shick, Frank Lechermann, Alexander Lichtenstein. 2018-01-11. The role of non-spherical double counting in DFT+DMFT: total energy and structural optimization of pnictide superconductors. https://doi.org/10.1103/physrevb.97.201116

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