Pentacene Molecules on Inert Surfaces

We study the energetics and dynamics of pentacene molecules in vacuum and saturated diamond (111) surface and silica surfaces. Force field molecular dynamics simulations are applied to capture the van de Waals type interactions among the pentacene molecules and the substrates. The herringbone arrangement of the molecules is found to be optimal both in vacuum and on various inert surfaces. A 90 degree rotation of the entire structure relative to that experimentally reported is identified on the silica surfaces.