Coalescence of Carbon Atoms on Cu (111) Surface: Emergence of a Stable Bridging-Metal Structure Motif

By combining first principles transition state location and molecular dynamics simulation, we unambiguously identify a carbon atom approaching induced bridging metal structure formation on Cu (111) surface, which strongly modify the carbon atom coalescence dynamics. The emergence of this new structural motif turns out to be a result of the subtle balance between Cu-C and Cu-Cu interactions. Based on this picture, a simple theoretical model is proposed, which describes a variety of surface chemistries very well

Density-functional calculations of the structure and stability of C 240

Density-functional calculations have been performed to determine optimized geometries and energies of C240 using the divide-and-conquer method. Six initial geometries were considered, resulting in convergence to two optimized configurations. The formation energies of the optimized structures are separated by approximately 0.07 eV/carbon atom. The lower-energy structure is highly spherical in agreement with preliminary studies and experimental observations. The higher-energy structure is polyhedrally faceted. The results support the conclusion that the most stable form of large carbon clusters is that of dense spherical caged structures

(1S*,2R*,4aS*,6aS*,6bR*,10S*,12aR*,14aS*)-10-Hydr­oxy-1,2,6a,6b,9,9,12a-hepta­methyl­perhydro­picene-4a,14a-carbolactone

The title compound, C30H48O3, was extracted from the plant Dracocephalum rupestre Hance. The mol­ecule contains five fused cyclo­hexane rings and one five-membered lactone ring. Inter­molecular O—H⋯O hydrogen bonds between the hydroxyl and carbonyl groups link the mol­ecules into chains along [010]. The absolute structure has not been determined