First-Principles Study of the High-Temperature Phase of Li2NH

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• 作者：Giacomo Miceli ; Michele Ceriotti ; Stefano Angioletti-Uberti ; Marco Bernasconi ; Michele Parrinello
• 刊名：Journal of Physical Chemistry C
• 出版年：2011
• 出版时间：April 14, 2011
• 年：2011
• 卷：115
• 期：14
• 页码：7076-7080
• 全文大小：866K
• 年卷期：v.115,no.14(April 14, 2011)
• ISSN：1932-7455

文摘

On the basis of ab initio molecular dynamics simulations, we propose that the Fm3̅m symmetry of the high-temperature (above 356 K) phase of Li₂NH results from dynamical disorder due to fast diffusion of Li interstitials and a slower diffusion of Li vacancies. Still, most of the NH groups point tetrahedrally toward the nearest Li vacancy in a geometry reminiscent of the low-temperature Fd3̅m phase. Li diffusion appears at high temperature due to breaking of the tetrahedral clusters of Li interstitials present in our model of the low-temperature Fd3̅m phase.