C_dat different levels of theory. (a)C_dby Eq. (28) withγ= 1.0,ξ= 0.5 (black), Eq. (19) with semi-empiricalγ(ϕ₀) in Eq. (24) forγ₊=γ= 1.0 andγ₋=ξγ= 0.5 (red), Eq. (19) withγ= 1.0 (blue) andγ= 0.5 (pink), with Eq. (5) (green). (b)C_dby Eq. (28) withγ= 0.1,ξ= 0.1 (black), Eq. (19) with semi-empiricalγ(ϕ₀) in Eq. (24) forγ₊=γ= 0.1 andγ₋=ξγ= 0.01 (red), Eq. (19) withγ= 0.1 (blue) andγ= 0.01 (pink). Insets in (a) and (b) areC_dat different levels of theory between potentials of −0.1 to 0.1 V.