Calderín L, González D J, González L E, López J M
Departamento de Física Teórica, Facultad de Ciencias, Universidad de Valladolid, 47011 Valladolid, Spain.
J Chem Phys. 2008 Nov 21;129(19):194506. doi: 10.1063/1.3020304.
We report on a study of several structural, dynamic, and electronic properties of liquid Sn at a thermodynamic state close to the triple point (573 K) and another one at a higher temperature (1273 K). This study has been performed by ab initio molecular dynamics simulations using 205 atoms and around 20 ps of simulation time. The calculated static structures show a good agreement with the available experimental data. The dynamic structure factors fairly agree with their experimental counterparts obtained by inelastic x-ray scattering experiments, which display inelastic side peaks. The calculated dispersion relations exhibit a positive dispersion, although not so marked as suggested by the experiment; moreover, its slope at the long-wavelength limit compares favorably with the experimental sound velocity. Electron densities near selected triplets of atoms are similar to those appearing in the solid phases, but these features have an extremely short lifetime, so they should not be considered as solid remnants in the melt.
我们报告了一项关于液态锡在接近三相点（573K）的热力学状态以及另一个在较高温度（1273K）下的若干结构、动力学和电子性质的研究。这项研究是通过使用205个原子和大约20皮秒的模拟时间进行的从头算分子动力学模拟来完成的。计算得到的静态结构与现有的实验数据吻合良好。动态结构因子与通过非弹性X射线散射实验获得的实验结果相当一致，该实验显示出非弹性边峰。计算得到的色散关系呈现出正色散，尽管不像实验所表明的那样显著；此外，其在长波长极限处的斜率与实验声速相比具有优势。选定原子三重态附近的电子密度与固相中的相似，但这些特征的寿命极短，因此不应将它们视为熔体中的固体残余物。
