New post from thomfrauen1950
New screened non-local exchange functional for semiconductors and their alloys. VASP
The performance of density functional theory depends largely on the approximation applied for the exchange functional. Accurate calculations for defects can be carried out with tuned hybrid functionals but the optimal parameters are not transferable. The BCCMS at the University Bremen has developed a new screened non-local exchange potential for semiconductors, with parameters based on the physical properties of the underlying microscopic screening and obeying the requirements for proper asymptotic behavior [Phys. Rev. B 102, 235168 (2020)]. This functional is Koopmans compliant and reproduces a wide range of band gaps. The only tunable parameter of the functional is transferable upon changing the cation or the anion isovalently, making the approach suitable for treating alloys on equal footing with the parent compounds. The computation time is somewhat below that of a PBE0 hybrid. The method has been implemented into the VASP package and tested. A patch to VASP 5 (as well as Manual and examples) can be obtained from Peter Deák ([email protected]) or Michael Lorke ([email protected]).