Comparative study of the electronic structure of(SN)xand its precursorS2N2using the extended tight-binding method

Abstract

We present detailed electronic structure, total density of states, and orbital density of states for polymeric sulfur nitride ${(\mathrm{SN})}_{x}$, and disulfur dinitride ${\mathrm{S}}_{2}$${\mathrm{N}}_{2}$, using the extended tight-binding method. To our knowledge this is the first time that ${\mathrm{S}}_{2}$${\mathrm{N}}_{2}$ has been investigated in any detail from the electronic-structure point of view. By a comparative study of ${\mathrm{S}}_{2}$${\mathrm{N}}_{2}$ and ${(\mathrm{SN})}_{x}$, S-$3p$ and N-$2p$ hybridization increases leading to a charge delocalization and hence enhanced conductivity. This is a direct consequence of the novel structure of ${(\mathrm{SN})}_{x}$. We have also been able to provide a complete interpretation of the ultraviolet and x-ray photoelectron spectra of ${(\mathrm{SN})}_{x}$. The intensities of various peaks are in good accord with those expected from our calculated symmetries of initial-state wave functions. Similar data are provided for ${\mathrm{S}}_{2}$${\mathrm{N}}_{2}$ with the hope that the experimental results will be forthcoming.