Investigations of Pressurized Lu–N–H Materials by Using the Hybrid Functional

Abstract

Recently, Lu−N−H materials were reported to have roomtemperature superconductivity, the Hubbard U correction on Lu's felectrons is necessary, and a constant U = 5.5 eV was applied to different Lu−N−H configurations. The following simulations demonstrate that different U values lead to different superconducting transition temperatures. Here, the structural and electronic Lu−N−H properties at high pressure (0−10 GPa) are systematically investigated based on the hybrid functional. We show that different Lu−N−H configurations should possess different U values varying from 6.4 to 7.4 eV. Furthermore, at pressures ranging from 0 to 1 GPa, the f and d band centers of N-doped LuH 3 show oscillation or even plateau, and the band gap of insulators also shows a platform, consistent with the pressure range for room-temperature superconductivity in Lu−N−H. Our work provides insight into understanding Lu−N−H materials and other hydrogen-rich superconductors based on rare-earth elements.