Short to medium range order and atomic dynamic property within the surface of nanoscale metallic glasses revealed by molecular dynamics simulations

•The surface of metallic glass has a propensity to transform into liquid-like phase upon deformation.•Low degree of medium-range order exists in the surface.•The atomic mobility of medium-range ordered super clusters is negatively correlated with the number of adjacent icosahedra clusters.•The surface of metallic glass consists of three consecutive sublayers.