Accession Number : AD1032510

Title :   Optical Absorption in Molecular Crystals from Time-Dependent Density Functional Theory

Descriptive Note : Technical Report,01 Sep 2015,31 Aug 2016

Corporate Author : Weizmann Institue of Science Rehovot United States

Personal Author(s) : Kronik,Leeor

Full Text :

Report Date : 18 Apr 2017

Pagination or Media Count : 13

Abstract : We address a major challenge for computational materials science based on density functional theory, by showing that fundamental gaps and optical spectra of molecular solids can be predicted quantitatively and non-empirically within the framework of time-dependent density functional theory (TDDFT), using the recently-developed optimally-tuned screened range-separated hybrid (OTSRSH) approach. We provide a comprehensive benchmark for the accuracy of our approach by considering the X23 set of molecular solids and comparing results obtained from TDDFT with those obtained from many-body perturbation theory in the GW-BSE approximation. We additionally compare results obtained from dielectric screening computed within the random phase approximation to those obtained from the computationally easier many-body dispersion approach and find that this influences the fundamental gap but there is little effect on the optical spectra. We therefore believe that the method is robust and can be used for studies of molecular solids that are typically outside the reach of computationally more intensive methods.

Descriptors :   dispersions , crystals , ionization potentials , dielectric permittivity , optical absorption , absorption spectra , computational chemistry methods , density functional theory , perturbation theory , band structures , excitation

Subject Categories : Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE