Electronic structure and total energy of interstitial hydrogen in iron: Tight binding models

TL;DR

This paper develops tight binding models to study the electronic structure and energy of interstitial hydrogen in iron, enabling better quantum mechanical simulations of hydrogen's effects on iron's mechanical properties.

Contribution

It introduces and compares simple and non-orthogonal tight binding models for hydrogen in iron, assessing their transferability and accuracy for key properties.

Findings

Good agreement with known segregation energies

Models enable atomistic simulation of hydrogen effects

Potential for improved mechanical property predictions

Abstract

An application of the tight binding approximation is presented for the description of electronic structure and interatomic force in magnetic iron, both pure and containing hydrogen impurities. We assess the simple canonical d-band description in comparison to a non orthogonal model including s and d bands. The transferability of our models is tested against known properties including the segregation energies of hydrogen to vacancies and to surfaces of iron. In many cases agreement is remarkably good, opening up the way to quantum mechanical atomistic simulation of the effects of hydrogen on mechanical properties.