01488nas a2200169 4500008004100000245011300041210006900154260001200223300001400235490000700249520089100256100002401147700001901171700002701190700002301217856007801240 2002 eng d00aCalculation of Thermodynamic, Electronic, and Optical Properties of Monoclinic Mg2NiH40 aCalculation of Thermodynamic Electronic and Optical Properties o c04/2002 a4879-48850 v913 a
Ab initio total-energy density functional theory is used to investigate the low temperature (LT) monoclinic form of Mg2NiH4. The calculated minimum energy geometry of LT Mg2NiH4 is close to that determined from neutron diffraction data, and the NiH4 complex is close to a regular tetrahedron. The enthalpies of the phase change to high temperature (HT) pseudo-cubic Mg2NiH4 and of hydrogen absorption by Mg2Ni are calculated and compared with experimental values. LT Mg2NiH4 is found to be a semiconductor with an indirect band gap of 1.4 eV. The optical dielectric function of LT Mg2NiH4 differs somewhat from that of the HT phase. A calculated thin film transmittance spectrum is consistent with an experimental spectrum.
1 aMyers, Whittier, R.1 aWang, Lin-Wang1 aRichardson, Thomas, J.1 aRubin, Michael, D. uhttps://facades.lbl.gov/publications/calculation-thermodynamic-electronic