Figure 4.

a) Comparison of the adsorption energies of H₂O molecule on the optimal sites of the Fe₁₀Co₁₀Ni₁₀Cu₇₀‐(111), Fe₂₅Co₂₅Ni₂₅Cu₂₅‐(111), pure Cu‐(111), and Pt‐(111) surfaces. b) Gibbs free energies for hydrogen adsorption at different optimal active sites of the catalyst surfaces. c) Computed differential charge densities for hydrogen adsorption on the optimal Cu site of the Fe₁₀Co₁₀Ni₁₀Cu₇₀‐(111) surface. Yellow and blue bubbles represent the positive and negative charges with an iso‐value of 0.002 e Å⁻³, respectively. d) PDOS of the Fe₁₀Co₁₀Ni₁₀Cu₇₀‐(111) surface after the H* adsorption on the optimal Cu site. The red dotted lines at the energy of zero indicate the Fermi level.