Figure 4
From: Substrate effect on hydrogen evolution reaction in two-dimensional Mo2C monolayers
The charge redistribution in the formation of the H–Mo bonds. The redistribution is calculated by subtracting charge densities of the isolated Mo2C \({\rho }^{{Mo}_{2}C}\left(r\right)\) and H atom \({\rho }^{H}\left(r\right)\) from that of the H absorbed Mo2C \({\rho }^{{Mo}_{2}C+H}\left(r\right)\), i.e., \({\rho }^{{Mo}_{2}C+H}\left(r\right)-[{\rho }^{{Mo}_{2}C}\left(r\right) + {\rho }^{H}\left(r\right)]\). The red and green iso-surfaces denote increasing and decreasing of the charge density in the bond formation, respectively.
