First-principles investigation of Mg₂CoH₅ complex hydride

来源期刊：中国有色金属学报(英文版)2009年第1期

论文作者：张健 周惦武 刘金水

文章页码：205 - 209

Key words：Mg₂CoH₅; density functional theory; electronic structure; formation enthalpy

Abstract: Within the framework of density functional theory, crystal structure parameters, physical properties, electronic structures and thermal stability of Mg₂CoH₅ complex hydride are comprehensively investigated. The optimized structural parameters including lattice constants, atomic positions and bond lengths are well close to the experimental data determined from X-ray and neutron powder diffraction. A detailed study on the energy band, density of states (DOS) and charge density distribution shows the orbital hybridization and bonding characteristics of the complex hydride. It is found that Mg₂CoH₅ is a semiconductor with a pseudo-gap of about 1.638 1 eV, and there is a mixed ionic-covalent bonding between Co and H in CoH₅ complexes embedded in the matrix Mg²⁺ cations. The calculated formation enthalpy of Mg₂CoH₅ is in good agreement with the experimentally determined value.

基金信息：the Program for Changjiang Scholars and the Innovative Research Team in University of China
the Ministry of Science and Technology of China