Efficacy of surface error corrections to density functional theory calculations of vacancy formation energy in transition metals

TL;DR

This paper evaluates the accuracy of density functional theory in predicting vacancy formation energies in transition metals and investigates how surface error corrections can improve these predictions.

Contribution

It introduces a correction scheme for surface intrinsic errors in DFT calculations and assesses its effectiveness across different exchange-correlation functionals and metals.

Findings

Correction scheme improves DFT vacancy energy predictions

GGA functionals outperform LDA in accuracy

Surface error correction reduces discrepancy with experimental data

Abstract

We calculate properties like equilibrium lattice parameter, bulk modulus and monovacancy formation energy for nickel (Ni), iron (Fe) and chromium (Cr) using Kohn-Sham density functional theory (DFT). We compare relative performance of local density approximation (LDA) and generalized gradient approximation (GGA) for predicting such physical properties for these metals. We also make a relative study between two different flavors of GGA exchange correlation functional, namely, PW91 and PBE. These calculations show that there is a discrepancy between DFT calculations and experimental data. In order to understand this discrepancy in the calculation of vacancy formation energy, we introduce a correction for the surface intrinsic error corresponding to an exchange correlation functional using the scheme implemented by Mattsson et al. [Phys. Rev. B 73, 195123 (2006)] and compare the effectiveness of the correction scheme for Al and the 3d-transition metals.