In many statistical models of nuclear fragmentation it is assumed that the disassembly takes place in a volume larger than the normal nuclear volume. Nucleons and composites appear in this volume according to laws of equilibrium statistical mechanics. The different particles are not supposed to overlap with each other, hence the available volume within which the particles can move freely is reduced. For typical nuclear cases we calculate this reduction.

• Received 21 July 1998

DOI:https://doi.org/10.1103/PhysRevC.59.845