▎ 摘　　要

The electronic band structure of graphene in the presence of spin-orbit coupling and transverse electric field is investigated from first principles using the linearized augmented plane-wave method. The spin-orbit coupling opens a gap of 24 mu eV (0.28 K) at the K(K-') point. It is shown that the previously accepted value of 1 mu eV, coming from the sigma-pi mixing, is incorrect due to the neglect of d and higher orbitals whose contribution is dominant due to symmetry reasons. The transverse electric field induces an additional (extrinsic) Bychkov-Rashba-type splitting of 10 mu eV (0.11 K) per V/nm, coming from the sigma-pi mixing. A "miniripple" configuration with every other atom shifted out of the sheet by less than 1% differs little from the intrinsic case.