DFTB Parameters for the Periodic Table: Part 1, Electronic Structure

Abstract

A parametrization scheme for the electronic part of the density-functional based tight-binding (DFTB) method that covers the periodic table is presented. A semiautomatic parametrization scheme has been developed that uses Kohn-Sham energies and band structure curvatures of real and fictitious homoatomic crystal structures as reference data. A confinement potential is used to tighten the Kohn-Sham orbitals, which includes two free parameters that are used to optimize the performance of the method. The method is tested on more than 100 systems and shows excellent overall performance.

Density-functional-based tight-binding parameterization of Mo, C, H, O and Si for studying hydrogenation reactions on molybdenum carbide

“…The electronic part of the parameters, as obtained by Wahiduzzaman et al [25], produces band structures in close agreement with DFT (PBE) reference data. Examples are given in Fig.…”

“…The new DFTB electronic parameters developed recently by Wahiduzzaman et al [25] considered many different phases and combinations of the elements in the periodic table and reproduce very well the DFT band structures of the target systems. These electronic parts of the DFTB parameters conveniently laid the foundation for bridging the gap between material systems and organic systems in DFTB.…”

“…In other words, one needs to make the new elements work with each of the elements in the older set. Instead of expanding the older parameter sets using this traditional approach, we took advantage of a recently developed DFTB parameter set (electronic part only) for the whole periodic table [25]. In this development, a semiautomatic parameterization scheme was used to build the electronic part of the DFTB parameters for the periodic table.…”

“…The electronic part of the DFTB energy comes directly from the DFTB pseudoatoms and parameters reported recently [25]. In this procedure, the confinement potentials are defined by two free parameters r 0 and σ and optimized to produce the band structures for a variety of crystal systems:…”

“…The valence shells and electronic configurations of the related pseudoatoms are listed in Table 1. For validation of the electronic part, the band structures of the periodic systems are calculated using the same method as in the literature [25] (DFT/PBE/TZP/ZORA in ADF/BAND [26]); molecular systems are calculated with DFT/PBE/ DZVP/GEN-A2 in deMon2k [27].…”