title: Approaches for the calculation of vibrational frequencies in liquids: comparison to benchmarks for azide/water clusters.
abstract: Ultrafast vibrational spectroscopy experiments, together with molecular-level theoretical interpretation, can provide important information about the structure and dynamics of complex condensed phase systems, including liquids. The theoretical challenge is to calculate the instantaneous vibrational frequencies of a molecule in contact with a molecular environment, accurately and quickly, and to this end a number of different methods have been developed. In this paper we critically analyze these different methods by comparing their results to accurate benchmark calculations on azide/water clusters. We also propose an optimized quantum mechanics/molecular mechanics method, which for this problem is superior to the other methods.
authors.affiliation: Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Shuzhou
authors.initials: S
authors.lastname: Li
authors.forename: J R
authors.initials: JR
authors.lastname: Schmidt
authors.forename: S A
authors.initials: SA
authors.lastname: Corcelli
authors.forename: C P
authors.initials: CP
authors.lastname: Lawrence
authors.forename: J L
authors.initials: JL
authors.lastname: Skinner
mesh_terms: D001386:Azides / Q000737:chemistry*; D002627:Chemistry, Physical / Q000379:methods*; D004581:Electronics; D004583:Electrons; D007477:Ions; D008958:Models, Molecular; D008962:Models, Theoretical; D009991:Oscillometry; D013053:Spectrophotometry / Q000379:methods*; D055672:Static Electricity; D014732:Vibration; D014867:Water / Q000737:chemistry*
chemical_list: D001386:Azides; D007477:Ions; D014867:Water