Table 2.

Symbols of physical quantities included in the derivation of the CTI formula in Eq. (10)

Quantity	Symbol	Unit
Absolute value of the charge of the electron	q	1.6 × 10−19 C
Avogadro’s number	A v	6.02 × 1023 1/mol
Extracellular and intracellular conductivities	σe and σi	S/m
Extracellular and intracellular activity coefficients of the jth charge carrier	${\gamma }_e^{\left(j\right)}\text{and}{\gamma }_i^{\left(j\right)}$	$0<{\gamma }_e^{\left(j\right)},{\gamma }_i^{\left(j\right)}<1$
Extracellular and intracellular concentrations of the jth charge carrier	$c_e^{\left(j\right)}\text{and}{c}_i^{\left(j\right)}$	mol/m3
Extracellular and intracellular mobility of the jth charge carrier	$m_e^{\left(j\right)}\text{and}{m}_i^{\left(j\right)}$	m2/Vs
Extracellular and intracellular water diffusion coefficients	$d_e^w\text{and}{d}_i^w$	m2/s
Extracellular and intracellular mobility tensors of the jth charge carrier	${\mathbf{M}}_e^{\left(j\right)}\text{and}{\mathbf{M}}_i^{\left(j\right)}$	m2/Vs
Extracellular and intracellular water diffusion tensors	${\mathbf{D}}_e^w\text{and}{\mathbf{D}}_i^w$	m2/s
Volume fraction of extracellular space	χ	0 < χ < 1
High-frequency and low-frequency conductivities	σH and σL	S/m
Conductivity tensor	C	S/m