2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/171633An exact formula for the minimal coordination numbers of the parallel packed bundle of rods is presented based on an optimal thickening scenario. Hexagonal and square lattices are considered.12 pages, 4 figures, to appear in J. Chem. PhysSoft Condensed MatterA formula for the minimal coordination number of a parallel bundletext