Guo Qiang, Ghaani Mohammad Reza, Nandi Prithwish K, English Niall J
Collaborative Innovation Center of Chemical Science and Engineering (Tianjin), Tianjin Key Laboratory of Applied Catalysis Science and Technology, College of Chemical Engineering and Technology , Tianjin University , Tianjin 300072 , P.R. China.
School of Chemical and Bioprocess Engineering , University College Dublin , Belfield , Dublin 4 , Ireland.
J Phys Chem Lett. 2018 Sep 20;9(18):5267-5274. doi: 10.1021/acs.jpclett.8b02270. Epub 2018 Aug 31.
Molecular-dynamics (MD) simulation of triaxially pressurized ice I up to 30 kbar at 240 K (with sudden mechanical pressurization from its ambient-pressure structure) has been carried out with both the single-particle mW and atomistic TIP4P-Ice water potentials on systems of up to ∼1 million molecules, for times of the order of 100 ns. It was found that the TIP4P-Ice systems adopted a high-density liquid state above ∼7 kbar, while densification of the mW systems retained essentially crystalline order, owing to a failure for the tetrahedral network to break down appreciably from its ice I lattice structure. Both are intermediate states adopted along the path toward respective thermodynamically stable states (and with pressure removal show reversion to I for mW and to supercooled liquid for TIP4P-Ice), similar to recent ice electro-freezing simulations in "No Man's Land". Densification kinetics showed faster mW-system adaptation.
在240K温度下对高达30千巴的三轴加压冰I进行了分子动力学（MD）模拟（从其常压结构进行突然机械加压），使用单粒子mW和原子级TIP4P - Ice水势，对多达约100万个分子的系统进行了模拟，模拟时间约为100纳秒。研究发现，TIP4P - Ice系统在约7千巴以上呈现出高密度液态，而mW系统的致密化基本保持晶体有序，这是由于四面体网络未能从其冰I晶格结构中明显分解。两者都是沿着各自朝向热力学稳定状态的路径所采用的中间状态（并且去除压力后，mW系统显示恢复为冰I，TIP4P - Ice系统恢复为过冷液体），类似于最近在“无人区”进行的冰电冷冻模拟。致密化动力学表明mW系统的适应性更快。
