Smoluchowski Institute of Physics, Jagiellonian University, Łojasiewicza 11, 30-348 Kraków, Poland.
Department of Mechanical Engineering, Pennsylvania State University, University Park, Pennsylvania 16802, United States.
J Phys Chem Lett. 2022 Jan 20;13(2):628-633. doi: 10.1021/acs.jpclett.1c03867. Epub 2022 Jan 12.
Modeling chemical reactions in condensed phases is difficult. Interaction potentials (or force fields) like ReaxFF can perform this modeling with a high overall accuracy, but the disadvantage of ReaxFF is a low simulation speed arising from costly algorithms, in particular charge equilibration. Therefore, we reparametrized ReaxFF to incorporate Coulomb forces into other terms of the force field. Because of this change, our charge-implicit ReaxFF-CHO is >2 times faster than the original parametrization. Despite the lack of explicit electrostatic interactions, our potential can correctly model the reactions and densities of systems containing carbon, hydrogen, and oxygen atoms. We have used the new potential to simulate bombardment of trehalose by water clusters. It has been observed experimentally that these water projectiles can increase the sensitivity of secondary ion mass spectrometry by more than an order of magnitude, but no explanation for this phenomenon was given. Our simulations show that the increase in the intensity of the recorded signal coincides with the emission of trehalose-water complexes.
在凝聚相中模拟化学反应具有一定难度。ReaxFF 等相互作用势（或力场）可以实现高精度的建模，但 ReaxFF 的缺点是算法成本高，导致模拟速度较慢，特别是电荷平衡。因此，我们重新参数化了 ReaxFF，将库仑力纳入力场的其他项中。由于这一改变，我们的电荷隐式 ReaxFF-CHO 的速度比原始参数化快 >2 倍。尽管缺乏显式静电相互作用，但我们的势能可以正确地模拟含有碳、氢和氧原子的系统的反应和密度。我们使用新的势能模拟了水团对海藻糖的轰击。实验观察到，这些水射流可以使二次离子质谱法的灵敏度提高一个数量级以上，但没有对此现象给出解释。我们的模拟表明，记录信号强度的增加与海藻糖-水配合物的发射一致。
