Electron and phonon spectra dynamics and features of phase transitions in sodium at P=0-100 GPa

TL;DR

This study investigates the electron and phonon spectra of sodium under pressures from 0 to 100 GPa, analyzing structural transitions and melting behavior using ab initio calculations to understand phase transition features.

Contribution

It provides detailed ab initio calculations of sodium's spectra and melting points under pressure, revealing spectral dynamics near phase transitions and melting curve maxima.

Findings

Calculated melting points align with experimental data.

Identified spectral features associated with structural transitions.

Analyzed phonon spectra dynamics near melting maxima.

Abstract

Electron and phonon spectra dynamics, as well as features of structural transitions and melting of sodium under pressure within range 0 to 100 GPa are investigated. Electron and phonon spectra of crystal sodium are calculated ab initio within the density functional theory by means of the LMTART-7 software package (Savrasov-Savrasov: 1992; Savrasov: 1996; Savrasov: 2004), allowing the fully potential method of linear muffin-tin orbitals. Using the Lindemann measure and the calculated phonon spectra the theoretical values of melting points corresponding to the experimental data (Gregoryanz, et al: 2005; Gregoryanz, et al: 2008) are obtained. Features of electron and phonon spectra dynamics in the melting curve maximum vicinity and within cI2->cI4 structural transition range are discussed.