Ab initio prediction of high-pressure structural phase transition in BaH2
2007 (English)In: Journal of Alloys and Compounds, ISSN 0925-8388, Vol. 446, 405-408 p.Article in journal (Refereed) Published
We have performed ab initio electronic structure calculations to calculate the structural properties and high-pressure phase transition in Barium dihydride (BaH2). Our results show that BaH2 crystallizes the orthorhombic phase (CoSi2-type structure) with Pnma space group at ambient conditions. A phase transition to the hexagonal (Ni2In-type structure) with P6(3)/mmc space group is found at pressure around 4 GPa. At the phase transition, the coordination number of hydrogen increases from 9 to 11 and the average bond length of Ba-H increases. The results show a band gap of 2.9 eV for orthorhombic and 1.8 eV for hexagonal phase. In addition, it was also found that more energy is required to desorb hydrogen atom from high-pressure phase as compared to ambient phase.
Place, publisher, year, edition, pages
2007. Vol. 446, 405-408 p.
metal hydrides, phase transition, high-pressure
IdentifiersURN: urn:nbn:se:uu:diva-151540DOI: 10.1016/j.jallcom.2006.12.103ISI: 000250822900086OAI: oai:DiVA.org:uu-151540DiVA: diva2:410396