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arXiv · 2102.11041

Tuning the range separation parameter in periodic systems

Wenfei Li·Vojtech Vlcek·Helen Eisenberg·Eran Rabani·Roi Baer·Daniel Neuhauser
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Abstract

Kohn-Sham DFT with optimally tuned range-separated hybrid (RSH) functionals provides accurate and nonempirical fundamental gaps for a wide variety of finite-size systems. The standard tuning procedure relies on calculation of total energies of charged systems and thus cannot be applied to periodic solids. Here, we develop a framework for tuning the range separation parameter that can be used for periodic and open boundary conditions. The basic idea is to choose the range parameter that results in a stationary point where the fundamental gap obtained by RSH matches the gap obtained from a G0W0 over RSH calculation. The proposed framework is therefore analogous to eigenvalue self-consistent GW (scGW). We assess the method for various solids and obtain very good agreement with scGW results.

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Wenfei Li, Vojtech Vlcek, Helen Eisenberg, Eran Rabani, Roi Baer, Daniel Neuhauser. 2021-02-18. Tuning the range separation parameter in periodic systems. https://arxiv.org/abs/2102.11041

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