Prediction of Vibrational Spectra fromAbInitio Theory

Abstract

Ab initio electronic structure theory provides potential energy and dipole moment surfaces that can be used to compute rovibrational term values and transition moments, either by normal mode analysis followed by rovibrational perturbation theory or through variational calculations. The accuracy of the theoretical spectra thus generated depends on the level of electronic structure theory and the nuclear motion treatment applied. This review surveys the currently available theoretical methods and their accuracy. Case studies are discussed to illustrate the present state of the art.

Insights for an Accurate Comparison of Computational Data to Experimental Absorption and Emission Spectra: Beyond the Vertical Transition Approximation

“…The comparison between experimental absorption and emission spectra and related computational values is likely one of the best examples of fruitful interaction between experimental and theoretical studies. , Actually, the development of methods in quantum chemistry owes much to the comparison with spectroscopic data while, on the other hand, computations have always been profitably used to assign and interpret experimental spectra, even when they were limited to empirical or semiempirical methods. More recently, remarkable advances in the development of computational methods for the study of medium/large size molecules in their electronically excited states, and new functionals for TD-DFT, have been paralleled by several studies (too many to exhaustively review here) comparing computed and experimental spectra or, more precisely, quantities derived from the experimental spectra and computed values. − Most of these studies were simply based on a comparison of the computed vertical excitation energy ( E V ) with experimental absorption maxima (ν max ).…”

Schwingungsdynamik in O−H···O-verbrückten Aggregaten: FTIR-Spektroskopie vom Nah- bis zum Ferninfraroten

“…Für eine anharmonische Schwingungsanalyse 24 kann beispielsweise die Potentialhyperfläche des Systems berechnet und die Schrödingergleichung der Kernbewegungen gelöst werden. [25][26][27] Effizienter ist jedoch ein störungstheoretischer Ansatz.…”

The story of NCN as a key species in prompt-NO formation

“…Ref. [86]) but are less frequently reported; they are marked in Table 2. The rotational constants B e in Table 2 are those calculated from equilibrium geometries.…”