A comparison of the electrostatic potential u and ionic concentrations ci generated by SMPBIC model using membrane surface charge density σ = 30 μC/cm2 or without any membrane surface charge (i.e., σ = 0). a)–c) report the results for hVDAC1 in a solution of KCl (0.14 mol/L), a solution of NaCl (0.1 mol/L), and a solution mixture of KCl (0.14 mol/L), NaCl (0.01 mol/L), MgCl2 (0.01 mol/L), and CaCl2 (0.00025 mol), respectively. Here, the values of potential and concentrations are defined by eqs. (31) and (32).