Nuclear quantum effects in ab initio dynamics: Theory and experiments for lithium imide
Nuclear quantum effects in ab initio dynamics: Theory and experiments for lithium imide
复制标题
从头算动力学中的核量子效应：亚胺锂的理论与实验
DOI：
--
复制
发表时间：
2010
期刊：
影响因子：
--
通讯作者：
M. Parrinello
中科院分区：
文献类型：
--
作者：
M. Ceriotti;Giacomo Miceli;A. Pietropaolo;D. Colognesi;A. Nale;M. Catti;M. Bernasconi;M. Parrinello
由于氢原子质量小，即使在室温下也表现出很强的量子行为。将这些效应包括在第一性原理计算中是具有挑战性的，因为传统技术需要巨大的计算工作量。在这里，我们介绍了最近发展的随机方案的第一个从头计算应用，该方案允许廉价地近似核量子效应。利用非弹性中子散射实验测量了储氢材料--亚胺锂的质子动量分布，并与量子恒温从头算动力学的结果进行了比较。对于这种纯粹的量子力学性质，我们在理论和实验之间取得了良好的一致性，从而证明了在不增加计算工作量的情况下改进复杂含氢材料的建模是可能的。©2010美国物理学会。
Owing to their small mass, hydrogen atoms exhibit strong quantum behavior even at room temperature. Including these effects in first-principles calculations is challenging because of the huge computational effort required by conventional techniques. Here we present the first ab initio application of a recently developed stochastic scheme, which allows to approximate nuclear quantum effects inexpensively. The proton momentum distribution of lithium imide, a material of interest for hydrogen storage, was experimentally measured by inelastic neutron-scattering experiments and compared with the outcome of quantum thermostatted ab initio dynamics. We obtain favorable agreement between theory and experiments for this purely quantum-mechanical property, thereby demonstrating that it is possible to improve the modeling of complex hydrogen-containing materials without additional computational effort. © 2010 The American Physical Society.