Analytical Approach to Phonon Calculations in the SCC-DFTB Framework

TL;DR

This paper presents an analytical reciprocal-space method for calculating phonon Hessians within the SCC-DFTB framework, offering improved accuracy and efficiency over traditional numerical methods for various periodic systems.

Contribution

It introduces a novel analytical approach for phonon calculations in SCC-DFTB, enhancing computational efficiency and accuracy for periodic materials.

Findings

Analytical method outperforms numerical differentiation in accuracy.

Efficient computation demonstrated on diverse materials.

Applicable to complex periodic systems like graphene and nanotubes.

Abstract

Detailed derivation of the analytical, reciprocal-space approach of Hessian calculation within the self-consistent-charge density functional based tight-binding framework (SCC-DFTB) is presented. This approach provides an accurate and efficient way for obtaining the SCC-DFTB Hessian of periodic systems. Its superiority with respect to the traditional numerical force differentiation method is demonstrated for doped graphene, graphene nanoribbons, boron-nitride nanotubes, bulk zinc-oxide and other systems.