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Full-Text Articles in Physical Sciences and Mathematics
Development Of Density-Functional Tight-Binding Methods For Chemical Energy Science, Quan Vuong
Development Of Density-Functional Tight-Binding Methods For Chemical Energy Science, Quan Vuong
Doctoral Dissertations
Density-functional tight-binding (DFTB) method is an approximation to the popular first-principles density functional theory (DFT) method. Recently, DFTB has gained considerable visibility due to its inexpensive computational requirements that confer it the capability of sustaining long-timescale reactive molecular dynamics (MD) simulations while providing an explicit description of electronic structure at all time steps. This capability allows the description of bond formation and breaking processes, as well as charge polarization and charge transfer phenomena, with accuracy and transferability beyond comparable classical reactive force fields. It has thus been employed successfully in the simulation of many complex chemical processes. However, its applications …
Extension Of Restricted Open-Shell Kohn-Sham Methodology To A Density-Functional Tight-Binding Framework, Reuben Szabo
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, …