Spectral signatures of semiconductor clusters: (CdSe)16 isomers

•Isomers of the (CdSe)16 cluster.•Optical spectra of (CdSe)16 isomers.•IR spectra of (CdSe)16 isomers.•Hyperpolarizability of (CdSe)16 isomers.•Ionization energies of (CdSe)16 isomers. The sensitivity of several experimentally accessible properties to the geometrical structure of the semiconductor (CdSe)16 cluster is explored by density functional theory. Our test set consists of eleven (CdSe)16 isomers belonging to various topological groups. For all isomers, the UV–visible and IR spectra have been simulated and vertical and adiabatic ionization energies, adiabatic electron affinities, polarizabilities and hyperpolarizabilities have been computed. The hyperpolarizability is found to be the most sensitive property to the isomer geometrical structure followed by optical and IR spectra. This work leads to the conclusion that reliable identification of an isomer requires a combination of experimental methods.