STRUCTURE OF HIGH-TEMPERATURE FLUID SELENIUM
STRUCTURE OF HIGH-TEMPERATURE FLUID SELENIUM
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高温流体硒的结构
DOI：
10.1103/physrevb.60.2441
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发表时间：
1999
影响因子：
3.7
通讯作者：
C. Bichara
中科院分区：
文献类型：
--
作者：
J. Raty;A. Saúl;J. Gaspard;C. Bichara
半经验紧束缚能模型开发硒。它包括s和p电子，以及经验的色散力的描述，证明在所研究的液体密度是必要的。通过拟合从头计算得到了能带结构参数。模拟的液体结构与最近的X射线散射和扩展的X射线吸收精细结构实验在很宽的温度和密度范围内是非常好的协议。Monte Carlo模拟结果表明，所观察到的复杂的液体结构是由于硒链的断裂和分支。总配位数是由一个，两个和三个配位原子之间的平衡而产生的。讨论了这些缺陷的作用与液体的电导率的关系，即在高压下观察到的超导体-金属和金属-非金属的转变。
A semiempirical tight-binding energy model is developed for selenium. It includes s and p electrons as well as an empirical description of the dispersion forces that proves necessary at the liquid densities under study. The band-structure parameters are obtained by fitting ab initio calculations. The simulated liquid structures are in very good agreement with the most recent x-ray scattering and extended x-ray absorption fine-structure experiments in a broad temperature and density range. The Monte Carlo simulations performed show that the complex liquid structures observed result from the breaking and branching of the selenium chains. The total coordination number is shown to result from the balance between one-, two-, and threefold coordinated atoms. The role of these defects is discussed in relationship with the electrical conductivity of the liquid, ie, the semiconductor-metal and metal-nonmetal transitions observed at high pressures.