Investigation of changes in crystal and electronic structures by hydrogen within LaNi_5 from first-principles

摘要

Hydrogenation of LaNis P6/mmm up to saturation brings modifications of the crystal structure with two possible space groups for LaNi_5H_7, i.e. P6_3mc and P31c, determined experimentally. The energetics from computations within DFT allows pointing to the former as the most favorable one within a doubled cell along the c-axis with respect to LaNis. Results also show a compensation of the volume expansion effects favorable to the onset of magnetization by the chemical bonding involving Ni-H bond leading to vanishing moments.