C-C	Double dispersion Cole impedance model
CNLS	Complex nonlinear least-squares
CoV	Coefficient of variation
${\mathrm{CPE}}_{\mathrm{P}}$	Order of constant phase element
${\mathrm{CPE}}_{\mathrm{T}}$	Pseudo-capacitance of constant phase element
CPE	Constant phase element
EIA	Electronic Industries Alliance
EIS	Electrical impedance spectroscopy
FOC	Fractional-order capacitor
FOE	Fractional-order element
FOI	Fractional-order inductor
LCE	Legates’s coefficient of efficiency
MAE	Mean absolute error
NSE	Nash–Sutcliffe’s efficiency
${\mathrm{R}}^2$	Coefficient of determination
R, X	Real, imaginary parts of the complex impedance
Rec-2	Recurrent electrical impedance model for $n=2$ bifurcations
RMSE	Root mean squared error
SD	Standard deviation
WIA	Willmott’s index of agreement
$\tilde{x}$	Mean value