Anharmonic vibrational spectroscopy of the F-(H2O)n complexes, n=1, 2
Anharmonic vibrational spectroscopy of the F-(H2O)n complexes, n=1, 2
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DOI：
10.1021/jp0343483
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发表时间：
2003-06-19
影响因子：
2.9
通讯作者：
Gerber, RB
中科院分区：
文献类型：
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作者：
Chaban, GM;Xantheas, SS;Gerber, RB
我们报告了F-(H2O)和F-(H2O)(2)团簇的非谐波振动谱（基本音，第一泛音），在理论的MP2和CCSD(T)水平上计算，具有三重ζ质量的基集。通过相关校正振动自洽场（CC-VSCF）方法估计了非调和校正。在理论的CCSD(T)水平上得到的CC-VSCF非调和谱是首次在MP2以上的相关水平上报道的。我们发现，平均基集效应（TZP vs ag -cc- pvtz）约为30-40 cm(-1)，而不同水平的电子相关效应[MP2 vs CCSD(T)]的影响较小，为20-30 cm（-1）。然而，在F-(H2O)团簇的氢键O-H拉伸的情况下，基集效应要大得多，基本基团为100厘米（-1），第一个泛音为200厘米（-1）。我们的计算与F-(H2O)和F-(H2O)(2)体系有限的实验数据一致，并提供了可以指导进一步实验研究的额外信息。
We report anharmonic vibrational spectra (fundamentals, first overtones) for the F-(H2O) and F-(H2O)(2) clusters computed at the MP2 and CCSD(T) levels of theory with basis sets of triple-zeta quality. Anharmonic corrections were estimated via the correlation-corrected vibrational self-consistent field (CC-VSCF) method. The CC-VSCF anharmonic spectra obtained on the potential energy surfaces evaluated at the CCSD(T) level of theory are the first ones reported at a correlated level beyond MP2. We have found that the average basis set effect (TZP vs aug-cc-pVTZ) is on the order of 30-40 cm(-1), whereas the effects of different levels of electron correlation [MP2 vs CCSD(T)] are smaller, 20-30 cm(-1). However, the basis set effect is much larger in the case of the H-bonded O-H stretch of the F-(H2O) cluster amounting to 100 cm(-1) for the fundamentals and 200 cm(-1) for the first overtones. Our calculations are in agreement with the limited available set of experimental data for the F-(H2O) and F-(H2O)(2) systems and provide additional information that can guide further experimental studies.