The continuous melting transition of ethylene on graphite: A molecular dynamics study

Monolayers of Linear Molecules Adsorbed on the Graphite Basal Plane: Structures and Intermolecular Interactions

“…Simulations of both of these solids have been reported 103,106,107,112 that are in good agreement with the experimental data. These calculations were based on site-site models in which all C and H atoms were taken to be sites.…”

“… a Gas−solid energy parameters for these molecules have been estimated using Lorentz−Berthelot combining rules together with ε/ k = 28°, σ = 3.40 Å for the CC interactions. b The simulations of ethane and ethylene in graphite have been performed using eight-site and six-site models, respectively; see Klein et al. ,,, for details. c This quadrupole moment is parallel to the C−C axis; for estimates of all three moments, see Cheng and Klein …”

“…Ethane and Ethylene on Graphite. Both ethane 96-103 and ethylene [104][105][106][107][108][109][110][111][112][113][114][115] have been the subject of intensive study, in part because of the large number of monolayer 5, but for CO2. Here, the locations of the minima vary, as do the values of the energy at the minima: -1949 K for CO2 parallel to X* (a); -1937 K for a molecular orientation that is at 45°to the axes (b); and -1909 K for orientation perpendicular to the X axis (c).…”

Ordered phases of ethylene adsorbed on charged fullerenes and their aggregates

“…As the temperature increases, ethylene starts to translate and rotate; more and more molecules may escape their strict confinement. The fraction of molecules in the vertical configuration (defined as α < 50°) increases gradually from 10.3% at 1 K to 22.5% at 80 K. Klein and coworkers had reported a similar approximately linear increase for ethylene adsorbed on planar graphite [79] . It is worth mentioning that the orientation of individual molecules rarely changes during the duration of a simulation between tangential and vertical if the temperature is below 40–50 K.…”

“…First, as seen in the current work, ethylene on C 60 strongly prefers to form a commensurate phase because the corrugation is enhanced on convex surfaces [25,26] whereas commensurate phases on graphite escaped detection in all but Eden and Fain’s electron diffraction work [16,17] . Commensurate phases on graphite also failed to appear in molecular dynamics simulations [7,79] , even when the strength of the corrugation was deliberately increased [13,15] . Second, domain walls play an important role in two-dimensional phase transitions [13] ; C 60 is probably too small to support multiple domains.…”