Structures, energies of formation, electronic spectra and values of bulk moduli for crystalline modifications of small fullerene ${\mathrm{C}}_{28}$ with space groups $Fd3m$ and $P63∕mmc$ are calculated at the density-functional based tight-binding level. Both solid phases of ${\mathrm{C}}_{28}$ have very similar characteristics, which are compared with those of crystals of other small fullerenes—${\mathrm{C}}_{20}$ and ${\mathrm{C}}_{36}$. The important role of $\pi$ component of the $\mathrm{C}-\mathrm{C}$ bounds on the properties are shown.

• Received 19 October 2004

DOI:https://doi.org/10.1103/PhysRevB.72.012102