论文标题
固体氢中的高压II-III相变：最先进的摘要的见解
High-pressure II-III phase transition in solid hydrogen: Insights from state-of-the-art ab initio calculations
论文作者
论文摘要
使用随机相近似和扩散蒙特卡洛研究了固体氢中的高压II-III相变。发现这些方法之间的良好一致性证实，相对于半局部密度函数近似，对交换和相关的准确处理可将过渡压力增加100 GPA。然后，使用优化的杂种功能，我们揭示了由C2/C III期结构的平面图表不稳定性产生的第II期低对称结构。这种不稳定性削弱了C2/C的平面极化，导致II-III相变的众所周知的实验特征，例如颤音频率，红外活动和$ c/a $ lattice参数比率的急剧变化。最后，我们讨论了零点振动能，该振动能在稳定较低压力下稳定III方面起着重要作用。
The high-pressure II-III phase transition in solid hydrogen is investigated using the random phase approximation and diffusion Monte Carlo. Good agreement between the methods is found confirming that an accurate treatment of exchange and correlation increases the transition pressure by more than 100 GPa with respect to semilocal density functional approximations. Using an optimized hybrid functional, we then reveal a low-symmetry structure for phase II generated by an out-of-plane librational instability of the C2/c phase III structure. This instability weakens the in-plane polarization of C2/c leading to the well-known experimental signatures of the II-III phase transition such as a sharp shift in vibron frequency, infrared activity and $c/a$ lattice parameter ratio. Finally, we discuss the zero-point vibrational energy that plays an important role in stabilizing phase III at lower pressures.
