Energy of molecular structures in 12^{12}C, 16^{16}O, 20^{20}Ne, 24^{24}Mg, and 32^{32}S

International audienceThe energy of the 12 C, 16 O, 20 Ne, 24 Mg and 32 S 4n-nuclei has been determined within a generalized liquid drop model and assuming different planar and three-dimensional shapes of α-molecules : linear chain, triangle, square, tetrahedron, pentagon, trigonal bipyramid, square pyramid, hexagon, octahedron, octogon and cube. The potential barriers governing the entrance and decay channels via α absorption or emission as well as more symmetric binary and ternary reactions have been compared. The rms radii of the linear chains differ from the experimental rms radii of the ground states. The binding energies of the three-dimensional shapes at the contact point are higher than the ones of the planar configurations. The alpha particle plus A-4 daughter configuration leads always to the lowest potential barrier. The binding energy can be reproduced within the sum of the binding energy of n α particles plus the number of bonds multiplied by 2.4 MeV or by the sum of the binding energies of one alpha particle and the daughter nucleus plus the Coulomb energy and the proximity energy