▎ 摘　　要

New carbon allotropes can be designed by combining sp, sp(2) and sp(3) three hybridization states. And the hybridization states or coordination numbers of carbon atoms can be changed by applying high pressure on carbon materials. In this study, a common high pressure phase (named as TBBC) transformed from AB-stacking graphyne or THD-graphene is predicted. Its kinetic stability is examined using finite displacement method. We find that the sp(2) and sp(3) hybridized carbon atoms behave different vibration features at high frequency region. Both graphene-like and diamondlike vibration peaks occurs. Phase transition energy barriers from both graphyne and THD-graphene to TBBC are estimated. Electronic structure calculations show that the TBBC is an indirect semiconductor with a bandgap of 0.66 eV. The ideal tensile strength of TBBC is high in [0001] and [1 (1) over bar 00] directions, but is weak along [1 (2) over bar 10] direction. (c) 2018 Author(s).