Physical Sciences and Mathematics Commons^™

Extension Of Restricted Open-Shell Kohn-Sham Methodology To A Density-Functional Tight-Binding Framework, Reuben Szabo

WWU Graduate School Collection

The restricted open-shell Kohn-Sham (ROKS) approach for singlet excited states provides some advantages over the ∆-self-consistent-field (∆SCF) method, requiring only a single SCF procedure and avoiding the problem of variational collapse. While ROKS is a powerful tool for DFT, its application to density functional tight-binding (DFTB) could offer significant improvements in time complexity when compared to DFT, enabling excited-state simulations of extended molecular systems on longer timescales than ROKS. In this work we discuss the implementation of an RO-DFTB approach in the DFTB+ package, as well as its suitability for the study of organic dyes and photoactive compounds. For benchmarking, …