Orientational correlation in liquid hydrogen halides: the special case of HCl

Neutron diffraction experiments with isotopic H/D substitution from liquid HCl, HBr and HI are comparatively discussed. The hydrogen-hydrogen and hali de-hydrogen radial distribution functions suggest the presence of hydrogen bonding and marked orientational correlations only in the case of HCl. Litt le correlations are found for HI and HBr. An analysis of the molecular conf igurations compatible with the experimental data from HCl, generated via a Empirical Potential Monte Carlo Simulation, allows to discuss the extent of hydrogen bonding and electrostatic forces in this system. (C) 1998 Elsevie r Science B.V. All rights reserved.