“…Until recently the semiclassical approach to the relativistic mean field theory had been settled at the TF level only [12,17,24,25,26]. However, in the last years some amount of work has been addressed to develop the relativistic extended Thomas-Fermi (RETF) method [27,28,29,30], that includes gradient corrections of order h2 in the particle density and the scalar field. This new semiclassical approach has already been applied to the study of finite nuclei [28,31,32,33] and of the nuclear surface in the symmetric case [28,34,35].…”