Li Mengli, Chen Lu, Gui Lirong, Cao Shuo, Liu Di, Zhao Gang, Ding Mingcui, Yan Jinliang, Wang Dehua
School of Physics and Optoelectronic Engineering, Ludong University, Yantai 264025, P. R. China.
Phys Chem Chem Phys. 2021 Jan 28;23(3):2298-2304. doi: 10.1039/d0cp05707j.
Using Born-Oppenheimer ab initio molecular dynamics (BOAIMD) simulations, the high-density water (HDW) and low-density water (LDW) structures based on SCAN meta-GGA are compared with those based on PBE GGA. Compared with Car-Parrinello ab initio molecular dynamics (CPAIMD) simulations, BOAIMD simulations can produce more accurate results because no fictitious electron mass is introduced. At each state point, our simulations continue for 100 ps after the system reached equilibrium, which is the longest ab initio simulations of liquid water reported so far and can ensure an accurate statistical average. The influence of the size effect and nuclear quantum effect on structure is not considered in the present work, but only that of two different functionals on the structure is discussed. It is found that, in HDW, just as shown using CPAIMD simulations, the SCAN-based hydrogen-bonds (HBs) are more flexible than the PBE-based ones, which makes the structure based on SCAN obviously closer to the experimental results than that based on PBE. However, it is not the case in LDW, and the difference between the results based on these two functionals is very small.
使用玻恩-奥本海默从头算分子动力学（BOAIMD）模拟，将基于SCAN元广义梯度近似（meta-GGA）的高密度水（HDW）和低密度水（LDW）结构与基于PBE广义梯度近似（GGA）的结构进行比较。与卡-帕里尼罗从头算分子动力学（CPAIMD）模拟相比，BOAIMD模拟能产生更准确的结果，因为未引入虚拟电子质量。在每个状态点，系统达到平衡后我们的模拟持续100皮秒，这是目前报道的关于液态水最长的从头算模拟，能够确保准确的统计平均值。本工作中未考虑尺寸效应和核量子效应对结构的影响，仅讨论了两种不同泛函对结构的影响。研究发现，在HDW中，正如使用CPAIMD模拟所显示的那样，基于SCAN的氢键（HBs）比基于PBE的氢键更灵活，这使得基于SCAN的结构明显比基于PBE的结构更接近实验结果。然而，在LDW中情况并非如此，基于这两种泛函的结果之间差异非常小。
