High transition temperature superconductivity originates from the Coulombic interaction between two adjacent charge reservoirs (hole and electron). The optimal transition temperature is given by the algebraic expression:

T_{C0}=k_{B}^{−1}β (ση/A)^{1/2}ζ^{−1}where ζ is the interaction distance (along the transverse axis), σ/

Ais the areal charge density per type I layer per formula unit for participating charges, η is the number of mediating layers (e.g., the number of cuprate planes), and β (= 0.1075 ± 0.0003 eV Å^{2}) is a universal constant; e^{–2}β is approximately twice the reduced electron Compton wavelength. The relevant experimental parameters and the calculated values of T_{C0}are listed under Tabulated results for 50 optimal high-T_{C}materials from seven superconductor families.