Local order in quenched states of simple atomic substances.

In any fluid or solid condensed phase, instantaneous atomic positions can be resolved into a combination of inherent packing and of vibrational deformation components. In principle the latter can be removed by quenching the system by (mass-weighted) steepest descent on the potential energy hypersurface. Inherent structures generated this way for a noble-gas model potential have been structurally analyzed, starting both from homogeneous liquid and from heterogeneous crystal-plus-liquid states. Quenched configurations from the homogeneous liquid show that the icosahedral mode of atom coordination is rare; instead the more appropriate description of inherent structural disorder for the model appears to be variation of coordination number from its most probable value 12.