Vibrational spectra of 4-n-pentyl-4'-cyanobiphenyl in a liquid crystalline cell have been studied by means of micro-Raman spectroscopy when an electric field was applied up to similar to 10(4) V/cm. To further elucidate the intramolecular changes upon the presence of the electric field, density functional theory calculations have been applied to 5CB molecule under various electric field strengths. The inter-ring C-C bond distance connecting two phenyl rings was found to be most affected along with the variance of the inter-ring torsional angle only by the electric field as high as similar to 5 x 10(7) WCM. (c) 2006 Elsevier B.V. All rights reserved.