  The impact of nanometer sized drops on solid surfaces is studied using
molecular dynamics simulations. Equilibrated floating drops consisting of short
chains of Lennard-Jones liquids with adjustable volatility are directed
normally onto an atomistic solid surface where they are observed to bounce,
stick, splash or disintegrate, depending on the initial velocity and the nature
of the materials involved. Drops impacting at low velocity bounce from
non-wetting surfaces but stick and subsequently spread slowly on wetting
surfaces. Higher velocity impacts produce an prompt splash followed by
disintegration of the drop, while at still higher velocity drops disintegrate
immediately. The disintegration can be understood as either a loss of coherence
of the liquid or as the result of a local temperature exceeding the
liquid-vapor coexistence value. In contrast to macroscopic drops, the presence
of vapor outside the drop does not effect the behavior in any significant way.
Nonetheless, the transition between the splashing and bouncing/sticking regimes
occur at Reynolds and Weber numbers similar to those found for larger drops.
