Quantum-chemical calculation of two-dimensional infrared spectra using localized-mode VSCF/VCI

14 December 2022, Version 2
This content is a preprint and has not undergone peer review at the time of posting.


Computational protocols for the simulation of two-dimensional infrared (2D IR) spectroscopy usually rely on vibrational exciton models, which require an empirical parametrization. Here, we present an efficient quantum-chemical protocol for predicting static 2D IR spectra that does not require any empirical parameters. For the calculation of anharmonic vibrational energy levels and transition dipole moments, we employ the localized-mode vibrational self-consistent field (L-VSCF) / vibrational configuration interaction (L-VCI) approach previous established for (linear) anharmonic theoretical vibrational spectroscopy [Panek and Jacob, ChemPhysChem 15, 3365–3377 (2014)]. We demonstrate that with an efficient expansion of the potential energy surface using anharmonic one-mode potentials and harmonic two-mode potentials, 2D IR spectra of metal carbonyl complexes and of dipeptides can be predicted reliably. We further show how the close connection between L-VCI and vibrational exciton models can be exploited to extract the parameters of such models from those calculations. This provides a novel route to the fully quantum-chemical parametrization of vibrational exciton model for predicting 2D IR spectra.


quantum chemistry
theoretical spectroscopy
vibrational spectroscopy
2D IR spectroscopy
anharmonic theoretical vibrational spectroscopy

Supplementary materials

Supporting Information
Additional tables and figures.

Supplementary weblinks


Comments are not moderated before they are posted, but they can be removed by the site moderators if they are found to be in contravention of our Commenting Policy [opens in a new tab] - please read this policy before you post. Comments should be used for scholarly discussion of the content in question. You can find more information about how to use the commenting feature here [opens in a new tab] .
This site is protected by reCAPTCHA and the Google Privacy Policy [opens in a new tab] and Terms of Service [opens in a new tab] apply.