Electronic structure and infrared spectrum of a W_nC^0,± (n=1–6) cluster

W_nC^0,± (n=1-6) clusters are investigated by using the density functional theory (DFT) at the B3LYP/LANL2DZ level. We find that the neutral, anionic and cationic ground state structures are similar within the same size, and constituted by substituting a C atom for one W atom in the structures of W_n+1 clusters. The natural bond orbital (NBO) charge analyses indicate that the direction of electron transfer is from the W atom to the 2p orbital of the C atom. In addition, the calculated infrared spectra of the W_nC^0,± (n=2-6) clusters manifest that the vibrational frequencies of neutral, anionic and cationic clusters are similar in a range of 80 cm^-1-864 cm^-1. The high frequency, strong peak modes are found to be an almost stretched deformation of the carbide atom. Finally, the polarizabilities of W_nC^0,± (n=1-6) clusters are also discussed.