Spectroscopic determination of the water dimer intermolecular potential-energy surface
Spectroscopic determination of the water dimer intermolecular potential-energy surface
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DOI：
10.1063/1.1476932
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发表时间：
2002-06-15
影响因子：
4.4
通讯作者：
Saykally, RJ
中科院分区：
文献类型：
--
作者：
Goldman, N;Fellers, RS;Saykally, RJ
采用PSSH（pseudo spectral split Hamiltonian）方法，通过对水分子本征态的严格计算，将分布多极ASP（anisotropic site potential）势形式拟合到微波、太赫兹和中红外腔衰荡（D2 O）（2）谱，确定了两个可极化的六维水分子间势能面.拟合的电位准确地再现大多数基态的振动-旋转-隧穿光谱，并产生良好的第二维里系数的H2O和D2 O。计算的二聚体结构和偶极矩是从微波光谱和高水平从头计算确定的那些接近，除了O-O距离（2.952埃）是显着短于目前公认的实验值。的二聚体结合能（4.85千卡/摩尔）是相当小的比公认的实验结果，但在最近的理论结果，作为受体开关和供体-受体交换隧穿势垒和环状水三聚体和四聚体的结构和结合能非常一致。(C)2002年美国物理学会。
Two polarizable six-dimensional water dimer intermolecular potential surfaces have been determined by fitting the distributed multipole ASP (anisotropic site potential) potential form to microwave, terahertz, and midinfrared cavity ringdown (D2O)(2) spectra via a rigorous calculation of the water dimer eigenstates with the PSSH (pseudo-spectral split Hamiltonian) method. The fitted potentials accurately reproduce most ground-state vibration-rotation-tunneling spectra and yield excellent second virial coefficients for both H2O and D2O. The calculated dimer structure and dipole moment are close to those determined from microwave spectroscopy and high level ab initio calculations, except that the O-O distance (2.952 Angstrom) is significantly shorter than the currently accepted experimental value. The dimer binding energy (4.85 kcal/mol) is considerably smaller than the accepted experimental result, but in excellent agreement with recent theoretical results, as are the acceptor switching and donor-acceptor interchange tunneling barriers and the cyclic water trimer and tetramer structures and binding energies. (C) 2002 American Institute of Physics.