Molecular dynamics simulation on the short-range structure of ZnBr2-ZnCl2 melt

The short-range structure of ZnBr2-ZnCl2 melts has been deduced from molecular dynamics (MD) simulation by using the experimental interference function Q(.)i(Q). The pair potential employed was the modifications of the Born-Mayer-Huggins-type with the Busing approximation without the dispersion terms. The average coordination numbers of Br around Zn were calculated to be about 4, 3, 2, and I in 100, 75, 50, and 25 mol% ZnBr2 melts, respectively. In contrast, the numbers of Cl increased with increasing concentration of ZnCl2. Then, the average coordination numbers of anions around Zn were always almost 4, showing the existence of [ZnBrnCl4 -n](2-) (n = 0-4) species in all systems. Furthermore these tetrahedral units formed corner-sharing networks in the melts. The calculated results reproduced the experimental structural features declared by Raman spectroscopic and neutron diffraction studies. (c) 2004 Elsevier Ltd. All rights reserved.