Calculations of the thermal conductivities of ionic materials by simulation with polarizable interaction potentials.
Calculations of the thermal conductivities of ionic materials by simulation with polarizable interaction potentials.
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DOI：
10.1063/1.3086856
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发表时间：
2009-03
期刊：
影响因子：
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通讯作者：
N. Ohtori;M. Salanne;P. Madden
中科院分区：
文献类型：
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作者：
N. Ohtori;M. Salanne;P. Madden
为了用格林-久保方法进行计算机模拟计算带电可极化离子系统的导热系数，建立了周期边界条件下带电可极化离子系统的能流表达式。在第一性原理的基础上，通过与合适的凝聚相离子组态的从头计算结果进行“力匹配”，得到了LiCl、氯化钠和氯化钾的偶极极化势。对熔体的导热系数和其他输运系数的模拟结果与实验数据以及其他相互作用势的结果进行了比较。与实验的一致性几乎是定量的，特别是对氯化钠和氯化钾，这表明这些方法，也许有更复杂的形式的电势，可以用来预测熔体的导热系数，对于这些熔体来说，实验测定非常困难。结果表明，极化效应对能流有重要影响，对热导率的预测方案至关重要。
Expressions for the energy current of a system of charged, polarizable ions in periodic boundary conditions are developed in order to allow the thermal conductivity in such a system to be calculated by computer simulation using the Green-Kubo method. Dipole polarizable potentials for LiCl, NaCl, and KCl are obtained on a first-principles basis by "force matching" to the results of ab initio calculations on suitable condensed-phase ionic configurations. Simulation results for the thermal conductivity, and also other transport coefficients, for the melts are compared with experimental data and with results obtained with other interaction potentials. The agreement with experiment is almost quantitative, especially for NaCl and KCl, indicating that these methodologies, perhaps with more sophisticated forms for the potential, can be used to predict thermal conductivities for melts for which experimental determination is very difficult. It is demonstrated that the polarization effects have an important effect on the energy current and are crucial to a predictive scheme for the thermal conductivity.