Structural and electronic properties of glassy GeSe₂ surfaces

We report first-principles structural models of surfaces of glassy GeSe₂ (g-GeSe₂). The structural properties of bulk and surface g-GeSe₂ are compared with recent experimental data. The first diffraction peaks in the partial structure factors are accurately reproduced in both the surface and bulk models. We also examine the transition of the local bonding environment from the bulk to the surface. The surface reconstruction involves creation of several edge-sharing tetrahedra and electronic states are easily delocalized through rings formed in the reconstruction.