title: Orientational ordering of N2O molecules adsorbed on graphite (0001): A novel commensurate pinwheel structure
abstract: The structure and orientational ordering of N2O molecules physisorbed on graphite (0001) is investigated applying x-ray, neutron, and low-energy electron diffraction techniques. Combining the results of the three techniques, we find that N2O forms a highly ordered, hexagonal, commensurate (sqrt[21]xsqrt[21])R10.89 degrees phase. The unit cell contains seven molecules which are arranged in a seven-sublattice pinwheel structure, unexpected for linear molecules on a hexagonal lattice. Potential energy calculations corroborate these results.
authors.affiliation: Institut fur Physik, Johannes Gutenberg-Universitat, D-55099 Mainz, Germany.
authors.initials: B
authors.lastname: Leinbock
authors.initials: B
authors.lastname: Kromker
authors.initials: H
authors.lastname: Wiechert
authors.initials: M
authors.lastname: Hofmann