Interatomic potentials calculated from equations of state: Limitation of finite strain to moderate K′
Interatomic potentials calculated from equations of state: Limitation of finite strain to moderate K′
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DOI：
10.1029/93gl00388
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发表时间：
1993-04
影响因子：
5.2
通讯作者：
A. Hofmeister
中科院分区：
文献类型：
--
作者：
A. Hofmeister
通过计算固定结构的隐式原子间势来研究状态方程 (EOS) 有效的条件。三阶欧拉有限应变仅在 ∼3.8 < K′o < B 时产生物理真实势。上限 B 取决于长程吸引势相对于排斥势的大小，对于中性固体或不可压缩材料（例如，氩或 MgO）为 ∼6，对于离子或软固体（例如，NaCl）为 ∼8。因此，对于 K'o 通常占据的范围，三阶产生合理的原子间势。如果 K''o 与三阶值的变化超过百分之几，则四阶的潜力是不现实的。 Vinet、Ferrante、Rose 和 Smith 的 EOS 应该用于具有高 K'o 的材料（例如气体或液体），因为它对所有弹性参数值都产生有效的势。
Conditions under which equations of state (EOS) are valid are investigated by calculating implicit interatomic potentials for fixed structures. Third-order Eularian finite strain yields physically realistic potentials only for ∼3.8 < K′o < B. The upper limit B depends on the size of the long range attractive potential relative to that of the repulsive potential, and is ∼6 for neutral solids or incompressible materials (e.g., argon or MgO), or ∼8 for ionic or soft solids (e.g., NaCl). Thus, 3rd order yields reasonable interatomic potentials for the range K′o commonly occupies. Potentials for 4th order are unrealistic if K″o varies by more than a few % from the 3rd order value. Vinet, Ferrante, Rose and Smith's EOS should be used instead for materials with high K′o (e.g., gases or liquids) because it yields valid potentials for all values of the elastic parameters.