Homogeneous SPC/E water nucleation in large molecular dynamics simulations
Homogeneous SPC/E water nucleation in large molecular dynamics simulations
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DOI：
10.1063/1.4928055
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发表时间：
2015-08-14
影响因子：
4.4
通讯作者：
Tanaka, Hidekazu
中科院分区：
文献类型：
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作者：
Angelil, Raymond;Diemand, Juerg;Tanaka, Hidekazu
我们进行直接的大分子动力学模拟均相SPC/E水成核，使用类似于4。10（6）个分子。我们的大型系统尺寸使我们能够测量极低且准确的成核速率，低至10（19）cm（-3）s（-1），有助于缩小实验测量速率之间的差距，接近10（17）cm（-3）s（-1）。我们还能够精确地测量尺寸分布，粘附效率，集群温度和集群内部密度。我们引入了一个新的函数形式来实现Yasuoka-Matsumoto成核速率测量技术（阈值法）。与成核模型的比较表明，经典成核理论高估了成核速率几个数量级。半唯象成核模型做得更好，在最坏的情况下预测率的24倍。与Lennard-Jones模拟中观察到的不同，后临界星系团的温度与运行平均温度一致。此外，我们观察到，后临界集群的密度非常略高，类似于5%，比散装液体。我们重新校准Hale型J与S标度关系使用实验和模拟数据，发现显着的一致性超过30个数量级的成核速率范围和180 K的温度范围。(C)2015 AIP Publishing LLC.
We perform direct large molecular dynamics simulations of homogeneous SPC/E water nucleation, using up to similar to 4 . 10(6) molecules. Our large system sizes allow us to measure extremely low and accurate nucleation rates, down to similar to 10(19) cm(-3) s(-1), helping close the gap between experimentally measured rates similar to 10(17) cm(-3) s(-1). We are also able to precisely measure size distributions, sticking efficiencies, cluster temperatures, and cluster internal densities. We introduce a new functional form to implement the Yasuoka-Matsumoto nucleation rate measurement technique (threshold method). Comparison to nucleation models shows that classical nucleation theory over-estimates nucleation rates by a few orders of magnitude. The semi-phenomenological nucleation model does better, under-predicting rates by at worst a factor of 24. Unlike what has been observed in Lennard-Jones simulations, post-critical clusters have temperatures consistent with the run average temperature. Also, we observe that post-critical clusters have densities very slightly higher, similar to 5%, than bulk liquid. We re-calibrate a Hale-type J vs. S scaling relation using both experimental and simulation data, finding remarkable consistency in over 30 orders of magnitude in the nucleation rate range and 180 K in the temperature range. (C) 2015 AIP Publishing LLC.