LOCAL ORDER IN LIQUID CHLORINE AND THE SHAPE OF GA-A(R) AND S(K)

The local order in four models of liquid chlorine is investigated by computer simulation. It is shown that it is possible to derive quantitative information on the microscopic local arrangement of molecules and atoms by looking at a few types of configuration which correspond to stable dimer geometries deformed by density effects. For each configuration, the number of nearest-neighbour molecules and atoms is obtained and the experimental density dependence of the number of atoms, lying below the first and second peaks of the atom-atom pair distribution function, is discussed in terms of microscopic configurations. The predictions of the different potential models are analysed and the different roles played by the isotropic and anisotropic site interactions are discussed. Finally, the features of the structure factor S(K) are explained in terms of microscopic ordered configurations and contributions due to atoms present in the first and other coordination shells.