Gregpawin, thank's a lot for taking time and answering my question.
Yes, I know about electron shells in alkali metal clusters. That's pretty well described in Jellium Model. The magic numbers there correspond to closed shells (analog of closed shells in noble gases from the Periodic Table). BTW, talking about noble gas cluster formed in supersonic jet, those also form magic number clusters but those are explained from geometrical point of view. The noble gas magic number clusters correspond to polyhedra formed by closely packed atoms, for example 55 (cuboicosohedron if I'm not wrong).
Thus, there are two reasons for magic numbers: electronic closed shells and geometrical closed shells. Both exhibit great energetical stability
OK, now back to my question.
Along with others, magic number clusters are formed in various strongly nonequlibrium processes
(laser ablation, supersonic jet expansion, arcing etc.). It means that thermodynamical control is unlikely. If we do not have thermodynamical control how can we talk about magic number clusters, which have higher stability
in terms of energy?
Uf...that rather puzzling...