Variable Curvature Slab Molecular Dynamics as a Method to Determine Surface Stress

摘要

A thin plate or slab, prepared so that opposite faces have different surfacestresses, will bend as a result of the stress difference. We have developed aclassical molecular dynamics (MD) formulation where (similar in spirit toconstant-pressure MD) the curvature of the slab enters as an additionaldynamical degree of freedom. The equations of motion of the atoms have beenmodified according to a variable metric, and an additional equation of motionfor the curvature is introduced. We demonstrate the method to Au surfaces, bothclean and covered with Pb adsorbates, using many-body glue potentials.Applications to stepped surfaces, deconstruction and other surface phenomenaare under study.