A fusion of the LAPW and the LMTO methods: the augmented plane wave plus muffin-tin orbital (PMT) method

TL;DR

This paper introduces a new full-potential computational method combining augmented plane waves and muffin-tin orbitals, enhancing efficiency and accuracy in electronic structure calculations for various materials.

Contribution

It develops a novel basis set approach that integrates APWs and MTOs, improving convergence and ease of use over existing methods.

Findings

Improved total energy convergence with smaller basis sets

Efficient description of localized orbitals like transition metal 3d

Demonstrated effectiveness on materials like Cu, Fe, Li, SrTiO3, and GaAs

Abstract

We present a new full-potential method to solve the one-body problem, for example, in the local density approximation. The method uses the augmented plane waves (APWs) and the generalized muffin-tin orbitals (MTOs) together as basis sets to represent the eigenfunctions. Since the MTOs can efficiently describe localized orbitals, e.g, transition metal 3$d$ orbitals, the total energy convergence with basis size is drastically improved in comparison with the linearized APW method. Required parameters to specify MTOs are given by atomic calculations in advance. Thus the robustness, reliability, easy-of-use, and efficiency at this method can be superior to the linearized APW and MTO methods. We show how it works in typical examples, Cu, Fe, Li, SrTiO$_3$, and GaAs.