the dimer configurations of TM (V, Cr, Mn, Fe and Co) on the surface of GY. The most stable adsorption site is the alkyne ring of GY for all single TM atom (V, Cr, Mn, Fe and Co)[@19]. Based on the most stable single TM atom adsorption configuration, we put the second TM on the surface. Two initial possible adsorption sites for the second TM are considered, as shown in Fig.\[fig1\],(1) H1 site is neighboring hexagonal ring and (2) H2 site is neighboring alkyne ring around the first one. We find that CON2 (both TM atoms are trapped in alkyne ring by -C$\equiv$C-) is the most stable configuration, as shown in Fig.\[fig1\]. The configurations of CON1 (one TM trapped in in alkyne ring and another adsorbed at the hollow site of hexagonal ring) are 1.097eV, 0.515eV, 0.573eV, 0.978eV, and 1.084eV per TM atom less stable than that of CON2 for V, Cr, Mn, Fe and Co, respectively. The results indicate that all the five TM dimers are chemisorbed on GY sheet with large adsorption energies (-2.780 eV , -1.256 eV , -0.942 eV , -3.096 eV and -2.200 eV per TM atom for V, Cr, Mn, Fe, and Co dimers, 