Nanoclusters and amorphous ice flakes built from water dimers

•Water aggregate into various clusters with the dominant of water dimers on Cd(0001) surface, and the amorphous ice nanoflakes are built exclusively from water dimers.•Driven by the electric field from a STM tip, the water dimers can hop across the surface, detach from a cluster with subsequent attaching to another, or rotate or diffuse within the amorphous ice nanoflakes.