The growth of monolayers of truxenone on Cu (111) is investigated using scanning tunneling microscopy (STM) and low energy electron diffraction (LEED). Two distinct molecular packing motifs are observed which exist individually at low and high coverage, and coexist at intermediate states.

"Organic/inorganic epitaxy: commensurate epitaxial growth of truxenone on Cu (111)" A. J. Ramadan, C. Nielsen, S. Holliday, T. S. Jones, I. McCulloch and L. A. Rochford

http://pubs.rsc.org/en/content/articlelanding/2016/ra/c6ra01541g#!divAbstract