Comparative study of the electronic structure of (SN)x and its precursor S2N2 using the extended tight-binding method

Abstract

We present detailed electronic structure, total density of states, and orbital density of states for polymeric sulfur nitride ${\left(\mathrm{SN}\right)}_x$, 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 ${\left(\mathrm{SN}\right)}_x$, 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 ${\left(\mathrm{SN}\right)}_x$. We have also been able to provide a complete interpretation of the ultraviolet and x-ray photoelectron spectra of ${\left(\mathrm{SN}\right)}_x$. 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.