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arXiv 1210.0280cond-mat.mtrl-sci
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固体氢氘IV相的质子转移

Proton Transfer in Phase IV of Solid Hydrogen and Deuterium

Hanyu Liu, Yanming Ma

摘要:

最近发现的固体氢和氘的第四相由两层交替的石墨烯状三分子环和未结合的H2分子组成,引起了极大的兴趣。然而,第四阶段的振动性质仍然知之甚少。本文报道了在250 ~ 350 GPa和300 ~ 500 K的压力范围内,用从头算变元胞分子动力学模拟预测的第四相固体氢和氘的质子转移和三个分子环在类石墨烯层中的同时转动.这种质子转移与石墨烯类层中分子的特定伸长密切相关,并且在分子伸长较大的过程中,随着压力的增加,质子转移变得更加明显。由于质子转移的结果,氢分子在类石墨烯层中的寿命很短,并且氢的振动是强烈的非谐振动。我们的研究结果提供了直接的解释观察到的拉曼光谱宽度突然增加的形成阶段IV和它的大幅度增加与压力。

英文摘要:

The recent discovery of phase IV of solid hydrogen and deuterium consisting of two alternate layers of graphenelike three-molecule rings and unbound H2 molecules have generated great interests. However, vibrational nature of phase IV remains poorly understood. Here, we report a peculiar proton transfer and a simultaneous rotation of three molecule rings in graphenelike layers predicted by ab initio variable cell molecular dynamics simulations for phase IV of solid hydrogen and deuterium at pressure ranges of from 250 to 350 GPa and temperature range of from 300 to 500 K. This proton transfer is intimately related to the particular elongation of molecules in graphenelike layers, and it becomes more pronounced with increasing pressure at the course of larger elongation of molecules. As the consequence of proton transfer, hydrogen molecules in graphenelike layers are short lived and hydrogen vibration is strongly anharmonic. Our findings provide direct explanations on the observed abrupt increase of Raman width at the formation of phase IV and its large increase with pressure.

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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