To take into account static correlation effects in the quasi-two-dimensional electron gas a screened Coulombic interaction between particles is studied. The Thomas-Fermi approximation is used and the potential screening appears as a function of the Wigner-Seitz density parameter r(s) and the effective width t of the system. With the self-consistent field theory applied to the modified deformable jellium, the ground-state energy per particle and the conditions for electron localization are obtained in terms of the interparticle distance and the screening parameter mu. A critical minimum characteristic width t(c) is obtained
below t(c) no long-range order is obtained. For larger widths a stable localized state is predicted at finite densities. (C) 2001 John Wiley & Sons, Inc.