论文标题
平均球形近似中的个体离子物种化学电位
Individual ion species chemical potentials in the Mean Spherical Approximation
论文作者
论文摘要
平均球形近似（MSA）是一种通常用于计算原始模型中离子能量学的热力学理论（即背景介电中带电的硬球离子）。但是，对于过多的化学潜力，早期的MSA制剂（被广泛采用）仅包括计算平均过量化学潜力（或平均活性系数）所需的术语。不包括化学势$μ_i$ $ i $的其他术语，因为它们的平均化学潜力总计为$ 0 $。在这里，我们得出这些术语以提供完全MSA的化学电位配方。结果是我们显示的$μ_i$的简单添加术语，是对先前MSA版本的定性改进。此外，我们的派生表明，MSA对全局电荷中立性的假设并非严格必要，因此MSA也适用于接近中性的系统。
The Mean Spherical Approximation (MSA) is a commonly-used thermodynamic theory for computing the energetics of ions in the primitive model (i.e., charged hard-sphere ions in a background dielectric). For the excess chemical potential, however, the early MSA formulations (which were widely adopted) only included the terms needed to compute the mean excess chemical potential (or the mean activity coefficient). Other terms for the chemical potential $μ_i$ of individual species $i$ were not included because they sum to $0$ in the mean chemical potential. Here, we derive these terms to give a complete MSA formulation of the chemical potential. The result is a simple additive term for $μ_i$ that we show is a qualitative improvement over the previous MSA version. In addition, our derivation shows that the MSA's assumption of global charge neutrality is not strictly necessary, so that the MSA is also valid for systems close to neutrality.
