Experimental estimation of orientational correlation in liquid bromine

An approximate method to deduce orientational correlations in liquids directly from experimental structure factors has been proposed and applied satisfactorily to liquid bromine. The result suggests that the most probable orientation realized in liquid bromine is ‘‘staggered parallel (∥)’’ orientation rather than ‘‘T’’ orientation proposed so far. The molecules in the ∥ orientation are located at about 4.15 Å which is the shortest separation from a central one, while the other molecules located beyond this distance are effectively uncorrelated in orientation. The orientation is found to be very similar to that observed in the crystalline state. Simple consideration of intermolecular potentials calculated for various orientations by use of a model potential including two-center Lennard-Jones potential with idealized point quadrupole supports the present results qualitatively.