Re-examining the electronic structure of germanium: A first-principle study

TL;DR

This study uses a novel ab-initio method to accurately compute the electronic and structural properties of germanium, achieving results that closely match experimental data.

Contribution

It introduces the BZW-EF method within a GGA-LCAO framework for self-consistent calculations of Ge's properties, demonstrating improved accuracy.

Findings

Theoretical indirect band gap of 0.65 eV matches experimental values.

Predicted lattice constant of 5.63 Å agrees with experimental data.

Calculated bulk modulus of 80 GPa.

Abstract

We report results from an efficient, robust, ab-initio method for self-consistent calculations of electronic and structural properties of Ge. Our non-relativistic calculations employed a generalized gradient approximation (GGA) potential and the linear combination of atomic orbitals (LCAO) formalism. The distinctive feature of our computations stem from the use of Bagayoko-Zhao-Williams-Ekuma-Franklin (BZW-EF) method. Our results are in agreement with experimental ones where the latter are available. In particular, our theoretical, indirect band gap of 0.65 eV, at the experimental lattice constant of 5.66 \AA{}, is in excellent agreement with experiment. Our predicted, equilibrium lattice constant is 5.63 \AA{}, with a corresponding indirect band gap of 0.65 eV and a bulk modulus of 80 GPa. We also calculated the effective masses in various directions with respect to the $\Gamma$ point.