Structure and diffusion in liquid complex hydrides via ab initio molecular dynamics

摘要: We have used density functional theory based ab initio molecular dynamics (AIMD) to study NaAlH${}_{4}$, LiBH${}_{4}$, LiNH${}_{2}$, and Li${}_{2}$BNH${}_{6}$ across a range of temperatures, above below the experimental melting temperature. elucidated structure, vibrational, diffusion characteristics these four materials. find: (i) In all cases, liquid state remains mixture ions found in solid state. (ii) The anions remain intact on average but undergo large deformations temperatures. (iii) case there is evidence that Li${}^{+}$ sublattice melts before anionic sublattice. (iv) find connection between increased anion-anion ordering reduced anion mobility even point, due long Coulombic interactions anions. (v) Finally, we has same major vibrational modes as solid, though lower frequency vibration rotation become more prominent with increasing