Hybrid functionals for heterogenous materials

Density Functional Theory provides a useful balance between accuracy and efficiency for electronic structure calculations of many molecules and solids. However, current exchange and correlation functionals, including semi-local and hybrid functionals, may be inaccurate in the description of the electronic properties of heterogeneous systems, especially interfaces between systems with large dielectric mismatch. Here, we present a dielectric-dependent range-separated hybrid functional for the investigation of heterogeneous materials, including surfaces and interfaces. Building on previous work [1], we define a spatial dependent fraction of exact exchange inspired bythe static Coulomb-hole and screened-exchange (COHSEX) approximation. We show that the proposed dielectric hybrid functional accurately predicts the electronic structure of several non-metallic interfaces, 2D systems, nanoparticles, defective solids,and molecular crystals.

[1] H. Zheng, M. Govoni, and G. Galli, Phys Rev Mater3, 073803 (2019)