  A novel crystalline structure of hybrid monolayer hexagonal boron nitride
(BN) and graphene is predicted by means of the first-principles calculations.
This material can be derived via boron or nitrogen atoms substituted by carbon
atoms evenly in the graphitic BN with vacancies. The corresponding structure is
constructed from a BN hexagonal ring linking an additional carbon atom. The
unit cell is composed of 7 atoms, 3 of which are boron atoms, 3 are nitrogen
atoms, and one is carbon atom. It behaves a similar space structure as
graphene, which is thus coined as g-B3N3C. Two stable topological types
associated with the carbon bonds formation, i.e., C-N or C-B bonds, are
identified. Interestingly, distinct ground states of each type, depending on
C-N or C-B bonds, and electronic band gap as well as magnetic properties within
this material have been studied systematically. Our work demonstrates practical
and efficient access to electronic properties of two-dimensional nanostructures
providing an approach to tackling open fundamental questions in
bandgap-engineered devices and spintronics.
