Instituto de Fı́sica, UNAM, A.P. 20-364, México D.F.
J Phys Chem A. 2013 Jul 11;117(27):5642-9. doi: 10.1021/jp400483z. Epub 2013 Jun 28.
Endohedrally encapsulated hydrogen clusters doped with inert helium (H24He) and ionic lithium (H24Li(+)) are investigated. The confinement model is a nanoscopic analogue of the experimental compression of solid hydrogen. The structural and electronic properties of the doped hydrogen clusters are determined under the effects of pressure. The results are compared with these of the isoelectronic (pure) hydrogen counterpart H26 under similar physical conditions. Pressure increase rates with respect to H26 of approximately 1.1 are observed with the insertion of helium or lithium. The changes of geometrical structures and HOMO-LUMO gap energies with the pressure point out the pressure-induced metallization of the Li(+)-doped cluster. The computations are done using density functional theory in the form implemented for molecules; they include zero-point energy effects and, to our best knowledge, are the first of their kind.
研究了内包氢原子团簇掺杂惰性氦（H24He）和离子锂（H24Li(+)）。该约束模型是对固态氢实验压缩的微观模拟。在压力的影响下，确定了掺杂氢团簇的结构和电子性质。将这些结果与类似物理条件下等电子（纯）氢对应物 H26 的结果进行了比较。观察到插入氦或锂后，压力增长率约为 1.1 与 H26 相比。几何结构和 HOMO-LUMO 能隙能量随压力的变化指出了 Li(+)掺杂团簇的压致金属化。使用分子形式实现的密度泛函理论进行计算；它们包括零点能效应，据我们所知，这是此类计算中的首例。
