  We present Molecular Vibration Explorer, a freely accessible online database
and interactive tool for exploring vibrational spectra and tensorial
light-vibration coupling strengths of a large collection of thiolated
molecules. The `Gold' version of the database gathers the results from density
functional theory calculations on 2'800 commercially available thiol compounds
linked to a gold atom, with the main motivation to screen the best molecules
for THz and mid-infrared to visible upconversion. Additionally, the `Thiol'
version of the database contains results for 1'900 unbound thiolated compounds.
They both provide access to a comprehensive set of computed spectroscopic
parameters for all vibrational modes of all molecules in the database. The user
can simultaneously investigate infrared absorption, Raman scattering and
vibrational sum- and difference frequency generation cross sections. Molecules
can be screened for various parameters in custom frequency ranges, such as
large Raman cross-section under specific molecular orientation, or large
orientation-averaged sum-frequency generation (SFG) efficiency. The user can
select polarization vectors for the electromagnetic fields, set the orientation
of the molecule and customize parameters for plotting the corresponding IR,
Raman and sum-frequency spectra. We illustrate the capabilities of this tool
with selected applications in the field of surface-enhanced spectroscopy.
