This surface is the result of a Molecular Dynamics simulation of bi-axial compression of a CuZr (50% Cu, 50% Zr) metallic glass. The initial configuration was a CuZr cube with side length 100 nm. The glass had been produced by quenching from the melt at a rate of 1e11 K/s under fully periodic boundary conditions. In the compression simulation, the x- and y-directions were periodic, but the z-direction was free, hence the glass had free...