Effect of Hydrogenation on the Electronic Structure of HoNiSn - Ab Initio Calculations

The electronic and magnetic properties of HoNiSn alloy are studied by ab initio full relativistic full potential local orbital method within the local density approximation. The electronic structures are reported for two crystallographic structures: orthorhombic TiNiSi type and the hexagonal ZrNiAl-type structure. We also study the influence of hydrogenation on the electronic structure of $HoNiSnH_{0.66}$. Ab initio calculations have shown that in the both type of structures the Fermi level is located at the 4f peak of Ho, however we observed the modification of 3d peaks from nickel atoms below the Fermi energy. The hydrogenation leads to increase of the density of states at the Fermi level.