Improved representation of metallic bonding in atomistic simulations

Previous use of the Sutton-Chen glue potential to model deformation processes in aluminium showed marked deviation from the results of an ab initio simulation prior to yield. The origin of this problem is identified, and a revised scheme is suggested and tested. It is based on the fact that the atomic volume is a key quantity in the metallic bonding of sp bonded elements, and our idea should therefore have wide applicability to interatomic bonding models. The scheme uses a new approximate but rapidly computable formula for the local atomic volume in an inhomogeneous system.