Density functional theory study on the molecular structure and vibration spectra of fenbufen

This paper examines the comparative performance of different density functional theory (DFT) methods at various basis sets in predicting molecular and vibration spectra of gamma-oxo-[1,1′-biphenyl]-4-butanoic acid (fenbufen). DFT methods including mPW1PW91, HCTH, SVWN, PBEPBE, B3PW91 and B3LYP were investigated. Different basis sets including LANL2DZ, SDD, LANL2MB, CEP-4G, CEP-31G, and CEP-121G were also considered. It is remarkable that the mPW1PW91/LANL2DZ and mPW1PW91/SDD levels are clearly superior to all of the remaining DFT levels in predicting the structure of fenbufen. The calculated results also indicate that SVWN/LANL2DZ level show better performance in the vibration spectra prediction of fenbufen comparing other DFT methods.

Graphical abstractFigure optionsDownload full-size imageDownload as PowerPoint slideHighlights► In this study we study the molecular structures and vibration spectra of fenbufen. ► Wavenumber-linear scaling (WLS) method was applied to correct the calculated harmonic frequencies. ► mPW1PW91/LANL2DZ (SDD) is the best method for predicting the structure of fenbufen. ► SVWN/LANL2DZ is the best method for predicting the vibration spectra of fenbufen.