Jiang Xingxing, Zheng Yueshao, Xue Xiong-Xiong, Dai Jiayu, Feng Yexin
Hunan Provincial Key Laboratory of Low-Dimensional Structural Physics and Devices, School of Physics and Electronics, Hunan University, Changsha 410082, China.
Department of Physics, National University of Defense Technology, Changsha 410073, China.
J Chem Phys. 2020 Feb 21;152(7):074701. doi: 10.1063/1.5138253.
Understanding the behavior of H-He binary mixtures at high pressure is of great importance. Two more recent experiments [J. Lim and C. S. Yoo, Phys. Rev. Lett. 120, 165301 (2018) and R. Turnbull et al., ibid. 121, 195702 (2018)] are in conflict, regarding the miscibility between H and He in solids at high pressure. On the basis of first-principles calculations combined with the structure prediction method, we investigate the miscibility for solid H-He mixtures at pressures from 0 GPa to 200 GPa. It is found that there is no sign of miscibility and chemical reactivity in H-He mixtures with any H:He ratio. Moreover, instead of H-He mixtures, the calculated Raman modes of the N-H mixtures can better explain the characteristic peaks observed experimentally, which were claimed to be the H-He vibrational modes. These calculation results are more in line with the experimental findings by Turnbull et al. [Phys. Rev. Lett. 121, 195702 (2018)].
了解H-He二元混合物在高压下的行为具有重要意义。最近的两项实验[J. Lim和C. S. Yoo，《物理评论快报》120, 165301 (2018)以及R. Turnbull等人，同上，121, 195702 (2018)]在高压下固体中H和He的混溶性方面存在冲突。基于第一性原理计算并结合结构预测方法，我们研究了0 GPa至200 GPa压力下固体H-He混合物的混溶性。结果发现，任何H:He比例的H-He混合物中都没有混溶和化学反应性的迹象。此外，与H-He混合物不同，计算得到的N-H混合物的拉曼模式能够更好地解释实验中观察到的特征峰，这些特征峰曾被认为是H-He振动模式。这些计算结果与Turnbull等人[《物理评论快报》121, 195702 (2018)]的实验结果更为一致。
