Abstract

Two new potentials are proposed for the embedded-atom model for nickel: one that includes the thermal contribution of electrons to the energy and one that disregards it. The potential parameters are found based on the nickel properties in isobar p = 0 and under shock compression with pressures up to ~760 GPa. The best consistency with experimental data is obtained when the electron contribution to the energy is taken into account. The calculated Hugoniot adiabat is in good agreement with the true curve. The inclusion of the electron contribution significantly reduces temperature on the adiabat and increases the cold pressure. The calculated melting curve of the nickel models gradually goes up to 4518 K at 300 GPa and is barely affected by the presence of the electron contribution. The coordinates of the melting section on the shock adiabat are determined (starting at 275.8 GPa and 4422 K and finishing at 297.6 GPa and 4499 K). The phase diagram of nickel with a stable bcc phase region at pressures above 110–130 GPa is proposed. Tables with the energies and pressures of the models at compression ratios up to 1.8182 are presented.

中文翻译：

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镍的计算机模拟和分子动力学方法中的电子贡献计算

摘要

对于镍的嵌入原子模型，提出了两种新的电势：一种包括电子对能量的热贡献，另一种不考虑电子。根据等压线p中的镍特性找到潜在参数= 0且在压力高达〜760 GPa的冲击压缩下。当考虑电子对能量的贡献时，可获得与实验数据的最佳一致性。计算得出的Hugoniot绝热材料与真实曲线非常吻合。包含电子的贡献显着降低了绝热体上的温度并增加了冷压。镍模型的计算熔解曲线在300 GPa时逐渐上升至4518 K，几乎不受电子贡献的影响。确定了冲击绝热体上熔化段的坐标（从275.8 GPa和4422 K开始，到297.6 GPa和4499 K结束）。提出了在110-130 GPa以上的压力下具有稳定bcc相区的镍的相图。