FASP: a framework for automation of Slater–Koster file parameterization

The self-consistent-charge density-functional tight-binding method (SCC-DFTB) is largely used for investigating systems of increasing complexity. However, the SCC-DFTB parameters are not available for the whole periodic table and some issues related to its transferability can limit its usefulness. The framework for automating the repulsion energy (E rep) parameterization uses reference chemical models to parameterize the repulsion term of the SCC-DFTB. The aim is to provide a straightforward and accessible manner to obtain accurate SCC-DFTB E rep parameters automatically. Large number of reference chemical models can be simultaneously used to increase the accuracy and transferability of the parameters with respect to the total energies and derived properties. SCC-DFTB parameters for the C, O, N, H set were obtained. The results are in good agreement with the well-established SCC-DFTB parameters available for this test case. Extensions to include other properties such as reaction energies in the E rep parameterization are briefly discussed.