Exploring positron characteristics utilizing two new positron-electron correlation schemes based on three electronic-structure calculation methods

TL;DR

This paper introduces two new positron-electron correlation schemes based on three electronic-structure methods, improving the accuracy of positron lifetime and affinity calculations with validation against experimental data.

Contribution

The study develops gradient-corrected correlation forms and compares three electronic-structure methods, demonstrating improved accuracy and agreement with experiments for positron properties.

Findings

PAW method achieves near-perfect agreement with FLAPW for positron properties.

The new correlation form is competitive with experimental data.

ATSUP method's competitiveness is reduced with advanced calculations.

Abstract

We make a gradient correction to a new local density approximation form of positron-electron correlation. Then the positron lifetimes and affinities are probed by using these two approximation forms based on three electronic-structure calculation methods including the full-potential linearized augmented plane wave (FLAPW) plus local orbitals approach, the atomic superposition (ATSUP) approach and the projector augmented wave (PAW) approach. The differences between calculated lifetimes using the FLAPW and ATSUP methods are clearly interpreted in the view of positron and electron transfers. We further find that a well implemented PAW method can give near-perfect agreement on both the positron lifetimes and affinities with the FLAPW method, and the competitiveness of the ATSUP method against the FLAPW/PAW method is reduced within the best calculations. By comparing with experimental data, the new introduced gradient corrected correlation form is proved competitive for positron lifetime and affinity calculations.