The optimized molecular structural parameters and UV-vis, IR and Raman spectra of a dye molecule with an open formula of 1,1,5-Tris(4-dimethylaminophenyl)-3-methyl-divinylene are determined by means of density functional theory (DFT) calculations using B3LYP/6-31G** formalism. Neutral and cationically charged molecules are used for DFT computations. C-C, C-C, and N-C bond distances of dimethylaminophenyl groups of the dye molecule are in reasonable agreement with the experimental and theoretical C-C, C=C, and N-C bond lengths of the group reported in the literature. Because Vis-NIR region is near UV-Vis region in the electromagnetic spectra, calculated maximum wavelengths of UV-vis spectra are close to those of the experimental VIS-NIR spectra reported. C-C stretching frequencies calculated for dimethylaminophenyl, alkene, and benzene ring groups are also in good agreement with experimentally reported values. All calculated frequencies fall within 2.2% of the experimental frequency region. (C) 2009 Wiley Periodicals, Inc. Int J Quantum Chem 110: 1047-1047, 2010.