Electronic structures of solids made of C20 clusters

By performing first-principles calculations based on the density functional theory, we have investigated the optimized structures, cohesive energies and electronic properties of crystalline solids made of C-20 clusters. A very interesting result is found from the optimized diamond structure made of C-20's, where the dimered C-20 clusters, i.e., (C-20)(2) dimmers, are formed. Such (C-20)(2) dimers are then condensed by weak van der Waals interaction between them, leading to the formation of a molecular solid. We also found that one-dimensional molecular solid could be formed when C-20 clusters are head to head. Results on C-20 clusters arranged in the two-dimensional graphene structure and in fcc structure both show that there are significant coalescences of neighboring C-20 fullerenes, leading to metallic characters for both the graphene and fcc structures. (C) 2017 Author(s). All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license