2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/84841The potential profile across a biased molecular junction is calculated within the framework of a simple Thomas-Fermi type screening model. In particular, the relationship between this profile and the lateral molecular cross section is examined. We find that a transition from a linear potential profile to a potential that drops mainly near the molecule-metal contacts occurs with increasing cross section width, in agreement with numerical quantum calculations.6 pages, 5 figures, RevTeX4Chemical PhysicsMesoscale and Nanoscale Physicstext