TY - JOUR
T1 - Anharmonic vibrational spectroscopy of the F-(H2O)n complexes, n = 1, 2
AU - Chaban, Galina M.
AU - Xantheas, Sotiris S.
AU - Gerber, R. Benny
PY - 2003/6/19
Y1 - 2003/6/19
N2 - 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-ζ quality. Anharmonic corrections were estimated via the correlation-corrected vibration 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.
AB - 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-ζ quality. Anharmonic corrections were estimated via the correlation-corrected vibration 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.
UR - http://www.scopus.com/inward/record.url?scp=0037899604&partnerID=8YFLogxK
U2 - 10.1021/jp0343483
DO - 10.1021/jp0343483
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AN - SCOPUS:0037899604
SN - 1089-5639
VL - 107
SP - 4952
EP - 4956
JO - Journal of Physical Chemistry A
JF - Journal of Physical Chemistry A
IS - 24
ER -