Multi-reference extension to virtual crystal approximation pseudo-potentials

TL;DR

This paper introduces a multi-reference extension to the virtual crystal approximation pseudo-potential method, explicitly incorporating semi-core states for improved accuracy in atomic and crystalline calculations.

Contribution

It extends the VCA pseudo-potential scheme to include semi-core states through a fine-tuning process, enhancing transferability and accuracy.

Findings

Improved agreement with all-electron calculations for semi-core and valence states.

Enhanced transferability of pseudo-potentials across different atomic configurations.

More accurate lattice constant estimations in crystalline tests.

Abstract

In this study a computational method of the multi-reference VCA(virtual crystal approximation) pseudo-potential generation is presented. This is an extension of that proposed Ramer and Rappe [J. Phys. Chem. Sol. 61, 315(2000)], the scheme of which is in want of the explicit incorporation of semi-core states. To compensate this drawback, a kind of fine tuning applied to the non-multi-reference VCA pseudo-potential; the form of the pseudo-potential is slightly modified within the cut-off radius in order that the agreements between the pseudo-potential and all-electron calculations are guaranteed both for semi-core and valence states. The improvement in the present work is validated by atomic and crystalline test calculations for the transferability and the lattice constant estimation.