Are the triangles and the squares possible local atomic arrangements in the structure of amorphous silicon?

Abstract During the preparation of amorphous structures covalently bonded atoms tend to form their `natural configurations'. The measured radial distribution function is only a one-dimensional representation of the spatial atomic distribution, therefore efforts to develop new techniques for analyzing the atomic scale structure in three dimensions (`local natural configurations') are continuously being made. One way of ascertaining these natural configurations in a-Si is to consider the configuration of silicon fragments embedded inside large molecules. Insights into the structure of a-Si have been made by analyzing local configurations found in silicon fragments in large molecules. The source for these data is the Cambridge Structural Database (CSD). Out of almost 2600 Si–Si–Si fragments analyzed, a considerable number contain Si atoms in triangular or almost planar square arrangements.