Condensed phases of all-pentagon C20 cages as possible superconductors -: art. no. 161401

C-20 cages consisting only of pentagons have been synthesized in a gas phase. [H. Prinzbach et al., Nature (London), 407, 60 (2000)]. By performing first-principles calculations, we have found that the C-20 cages can form condensed phases in several dimensions. The most stable phase among the investigated ones is a simple-cubic-like (SCL) phase, which shows a metallic property. Meanwhile, a metastable one-dimensional phase (1D chain) is found to be a semiconductor. The computed band structure of a 1D chain shows high density of states near the Fermi level compared to the SCL phase, which is a promising sign of superconductivity under carrier doping.