PREDICTIONS AND SYSTEMATIZATIONS OF THE ZINCBLENDE WURTZITE STRUCTURAL ENERGIES IN BINARY OCTET COMPOUNDS

To systematize the wurtzite (W) versus zinc blende (ZB) structural preferences among the binary octet compounds, we have calculated the corresponding energy difference DELTA-E(W-ZB)LDF(AB) for thirteen AB compounds using the local-density formalism (LDF). We then uncovered a linear scaling between DELTA-E(W-ZB)LDF and an atomistic orbital-radii coordinate R(A,B) that can be simply calculated from the properties of the free A and B atoms. This permits perdictions of W-ZB energy differences for all binary compounds and exposes simple chemical trends, including the stabilization of the ZB form in the sequence B = O --> S --> Se --> Te for A(II)B(VI) and A = Ga --> Al --> In for A(III)B(V)'s. We propose new structural assignments for the low-temperature ground state of CdSe (ZB) and MgTe (NiAs type).