Ab initio determination of the atomistic structure of SixGe1-x alloy - art. no. 193202

We have performed systematical ab initio studies of the structural properti es of SixGe1-x alloy. To simulate the disordered alloy we use supercells wh ere the Si and Ge atoms are randomly placed with the constraint that the pa ir correlation functions agree with their values for a perfect random alloy within a given tolerance. We obtain that the Si-Si, Si-Ge, and Ge-Ge bond lengths dependence with composition varies only slightly for the different kinds of bonds, with topological rigidity parameters between 0.6 and 0.7.