All the calculations are performed on the basis of periodic spin-polarized density functional theory (DFT) within a plane wave basis set and projector augmented wave (PAW) formalism , as implemented in the Vienna ab initio simulation package (VASP 5.4) code. The generalized gradient approximation (GGA) with the parameterization of Perdew-Burke-Ernzerhof (PBE) is used for the exchange-correlation functional. We use 9 valence electrons for Co, 8 for Ru, 5 for N, 4 for C, and 1 for H. The plane wave energy cutoff is set to be 400eV. The convergence of energy and forces are set to be 1×10 -4 eV and 0.01eV/Å, respectively.