title: Communication: Vibrational sum-frequency spectrum of the air-water interface, revisited.
abstract: Before 2015, heterodyne-detected sum-frequency-generation experiments on the air-water interface showed the presence of a positive feature at low frequency in the imaginary part of the susceptibility. However, three very recent experiments indicate that this positive feature is in fact absent. Armed with a better understanding, developed by others, of how to calculate sum-frequency spectra, we recalculate the spectrum and find good agreement with these new experiments. In addition, we provide a revised interpretation of the spectrum.
authors.affiliation: Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: Yicun
authors.initials: Y
authors.lastname: Ni
authors.affiliation: Theoretical Chemistry Institute and Department of Chemistry, University of Wisconsin, Madison, Wisconsin 53706, USA.
authors.forename: J L
authors.initials: JL
authors.lastname: Skinner