Cubic C96: a novel carbon allotrope with a porous nanocube network

A novel cubic porous carbon allotrope C-96 carbon with intriguing physical properties was predicted. It has 96 atoms in the conventional cell, possessing a Pm (3) over barm space group. The basic building block of C-96 carbon is a planar six-membered carbon ring. The structural stability, mechanical properties, and dynamical properties of C-96 carbon were extensively studied. It is a semiconductor (1.85 eV) with a lower density (2.7 g cm(-3)) and a larger bulk modulus (279 GPa) and is stable under ambient conditions. The hardness of C-96 carbon (25 GPa) is larger than that of T carbon (5.6 GPa). Due to the structural porous feature and lower density, C-96 carbon can also be expected to be a good hydrogen storage material.