高压下的乙烷与甲烷：结构与稳定性
Ethane and methane at high pressures: structure and stability
AI总结：
本研究结合实验与理论方法，测定了高压下乙烷的结晶点、低压相结构及新相变，验证了甲烷的高压结构，并给出二者的状态方程，为其高压相对稳定性研究提供依据。
摘要：
我们分别采用X射线衍射、拉曼光谱以及USPEX（从头算演化结构搜索）算法，对300K温度下、压强最高达120GPa的乙烷和甲烷开展了实验与理论结合的研究。对于乙烷，我们测定了其室温下的结晶压强为2.7GPa，并确定了低压晶体结构（A相）。该晶体结构为取向无序的塑性相，与已知的低温乙烷晶体结构存在差异。此外，我们首次发现压强诱导的相变：在13.6GPa时转变为单斜B相，该结构经实验结果与理论预测良好吻合得到解析。对于甲烷，我们的X射线衍射测量结果与此前报道的高压结构及状态方程（EOS）一致。我们测定了乙烷和甲烷的状态方程，为讨论二者在高压下的相对稳定性提供了坚实基础。
英文摘要：
We have performed a combined experimental and theoretical study of ethane and methane at high pressures up to 120 GPa at 300 K using x-ray diffraction and Raman spectroscopy and the USPEX ab-initio evolutionary structural search algorithm, respectively. For ethane, we have determined the crystallization point, for room temperature, at 2.7 GPa and also the low pressure crystal structure (Phase A). This crystal structure is orientationally disordered (plastic phase) and deviates from the known crystal structures for ethane at low temperatures. Moreover, a pressure induced phase transition has been identified, for the first time, at 13.6 GPa to a monoclinic phase B, the structure of which is solved based on a good agreement of the experimental results and theoretical predictions. For methane, our XRD measurements are in agreement with the previously reported high-pressure structures and EOS. We have determined the equations of state of ethane and methane, which provides a solid basis for the discussion of their relative stability at high pressures.
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。
