The transport and relaxation properties of a molecular supercooled liquid on an isobar are studied by molecular dynamics. The molecule is a rigid heteronuclear biatomic system. The diffusivity is fitted over four orders of magnitude by the power law [formula presented] with [formula presented] and [formula presented] The self-part of the intermediate scattering function [formula presented] exhibits a steplike behavior at the lowest temperatures. On cooling, the increase of the related relaxat...