Infrared (IR) spectroscopy is one of the important physicochemical methods in the chemists' arsenal. This spectroscopic technique observes intra-and intermolecular vibrational motions, as their resonant excitation energies lie in the IR region, i.e., approximately from 100 to 10 4 cm -1 (wavelengths from 0.1 mm to 780 nm). In addition to simple absorption/emission IR spectroscopy, there are other techniques, such as vibrational circular dichroism (VCD), which is sensitive to molecular chirality, vibrational Raman spectroscopy, inelastic neutron scattering (INS), infrared/ultraviolet (IR-UV) ion dip spectroscopy, infrared multiple photon dissociation (IRMPD) spectroscopy, various messenger-tagging methods (such as helium, nitrogen, or hydrogen molecular tag), that allow measuring spectra of ions, and vibrational sum frequency generation (VSFG) spectroscopy, that allows to probe molecular motions at the phase interfaces. All these vibrational spectroscopy methods allow us to inspect the properties of molecules, ions, and molecular aggregates in the gas, liquid, and solid phases and at the interfaces between phases. In addition to that, vibrational spectroscopic techniques are widely used in analytical chemistry. Even more, an important usage of IR spectroscopy includes astronomy and astrochemistry, with the existence of IR spectrometers on interplanetary probes and of various IR space telescopes, such as the recently retired Stratospheric Observatory For Infrared Astronomy (SOFIA) and recently launched James Webb Space Telescope (JWST) .