First-principles calculations of optical properties of Titanium nanochains

In this paper, optical properties of linear, dimerized, zigzag and ladder nanowires were reported using the full potential linearized augmented plane wave plus local orbital method (FLAPW + LO) and by incorporating the generalized gradient approximation (GGA). Also, the super cell approach, infinite and free standing periodic nanowires were applied. Optical properties such as dielectric function, energy loss function, optical conductivity and reflectivity of nanochains were investigated. Moreover, the results of nanochains were compared with the findings of the present author's previous works on the bulk and nanowires (NWs). The properties, especially reflectivity and static dielectric function, changed significantly with configuration. The static dielectric function increased slightly from 1.9 in the dimerized nanowire to 3.06 in the linear one. The negative value of the real dielectric function occurred in some frequencies of the dimerized nanochains. Furthermore, equilibrium structure and inter-atomic distance were calculated, the results of which were in agreement with those of the previous works. In addition, nanowire reflectivity spectra showed a number of distinct peaks, which could be attributed to the plasmon resonance.