TY - JOUR
T1 - Anharmonic vibrational spectroscopy calculations using the ab initio CSP method
T2 - Applications to H2CO3, (H2CO3)2, H2CO3-H2O and isotopologues
AU - Sagiv, Lior
AU - Hirshberg, Barak
AU - Gerber, R. Benny
N1 - Publisher Copyright:
© 2017 Elsevier B.V.
PY - 2018/10/25
Y1 - 2018/10/25
N2 - The anharmonic frequencies of the O–H and the C–O stretching modes of carbonic acid are calculated using the ab initio classical separable potentials approximation. In this approach, ab initio molecular dynamics simulations are used to determine an effective classical potential for each of the normal modes of the system. The frequencies are calculated by solving the time-independent Schrödinger equation for each mode using time-averaged potentials. Hydrogen-bonded carbonic acid dimer, carbonic acid–water complex and isotopologues of these systems were also studied, showing good agreement with experiments. Useful insights are obtained by Fourier transforming the effective potentials, which relates the computed quantum frequencies to the classical dynamics of the system. This approach is illustrated for the systems studied, including for the challenging anharmonic isotope effect. In conclusion, the ab initio CSP approximation yields results in good accord with experiments, and the method provides interpretations in terms of the dynamics of vibrational motions.
AB - The anharmonic frequencies of the O–H and the C–O stretching modes of carbonic acid are calculated using the ab initio classical separable potentials approximation. In this approach, ab initio molecular dynamics simulations are used to determine an effective classical potential for each of the normal modes of the system. The frequencies are calculated by solving the time-independent Schrödinger equation for each mode using time-averaged potentials. Hydrogen-bonded carbonic acid dimer, carbonic acid–water complex and isotopologues of these systems were also studied, showing good agreement with experiments. Useful insights are obtained by Fourier transforming the effective potentials, which relates the computed quantum frequencies to the classical dynamics of the system. This approach is illustrated for the systems studied, including for the challenging anharmonic isotope effect. In conclusion, the ab initio CSP approximation yields results in good accord with experiments, and the method provides interpretations in terms of the dynamics of vibrational motions.
KW - AICSP
KW - Ab initio CSP
KW - CSP
KW - Carbonic acid
KW - Classical separable potentials
KW - Quantum dynamics
KW - Vibrational spectroscopy
UR - http://www.scopus.com/inward/record.url?scp=85039866160&partnerID=8YFLogxK
U2 - 10.1016/j.chemphys.2017.12.015
DO - 10.1016/j.chemphys.2017.12.015
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AN - SCOPUS:85039866160
VL - 514
SP - 44
EP - 54
JO - Chemical Physics
JF - Chemical Physics
SN - 0301-0104
ER -