Abstract: A capacitor and capacitor-like device or any other device showing capacitive effects, including FETs, transmission lines, piezoelectric and ferroelectric devices, etc., with at least two electrodes, of which at least one electrode consists of or comprises a material or is generated as electron system, whose absolute value of the electronic charging energy as defined by the charging-induced change of Ekin+Eexc+Ecorr exceeds 10% of the charging-induced change of the Coulomb field energy of the capacitor according to E=Ecoul+Ekin+Eexc+Ecorr. Therein, E is the energy of a capacitor and Ecoul=Q2/2 Ccoul=Q2d/(2 ?0 ?x A), A is the area of the capacitor electrodes, d is the distance and ?0?x the dielectric constant between them. Ecorr describes the correlation energy, Ekin the electronic kinetic energy and Eexc the exchange energy of the electrode material.