Department of Chemistry, University of Southern California, Los Angeles, California 90089-0482, USA.
J Phys Chem A. 2010 Dec 16;114(49):12945-51. doi: 10.1021/jp108255k. Epub 2010 Nov 16.
We present full-dimensional potential energy surfaces (PESs) for hydrated chloride based on the sum of ab initio (H(2)O)Cl(-), (H(2)O)(2), and (H(2)O)(3) potentials. The PESs are shown to predict minima and corresponding harmonic frequencies accurately on the basis of comparisons with previous and new ab initio calculations for (H(2)O)(2)Cl(-), (H(2)O)(3)Cl(-), and (H(2)O)(4)Cl(-). An estimate of the effect of the 3-body water interaction is made using a simple 3-body water potential that was recently fit to tens of thousands of ab initio 3-body energies. Anharmonic, coupled vibrational calculations are presented for these clusters, using the "local monomer model" for the high frequency intramolecular modes. This model is tested against previous "exact" calculations for (H(2)O)Cl(-). Radial distribution functions at 0 K obtained from quantum zero-point wave functions are also presented for the (H(2)O)(2)Cl(-) and (H(2)O)(3)Cl(-) clusters.
我们提出了基于从头算（H(2)O）Cl(-)、（H(2)O）(2)和（H(2)O）(3)势能总和的水合氯化物的全维势能面（PES）。根据与先前和新的（H(2)O）(2)Cl(-)、（H(2)O）(3)Cl(-)和（H(2)O）(4)Cl(-)的从头算计算的比较，PES 被证明能够准确地预测最小值和相应的谐频。使用最近拟合了数万次从头算三体力能的简单三体水势能对三体水相互作用的影响进行了估计。使用高频内部分子模式的“局部单体模型”对这些团簇进行了非谐耦合振动计算。该模型通过先前对（H(2)O）Cl(-)的“精确”计算进行了测试。还为（H(2)O）(2)Cl(-)和（H(2)O）(3)Cl(-)团簇提供了从量子零点波函数获得的 0 K 时的径向分布函数。
