Theoretical design of global optimization algorithms can profitably ut
ilize recent statistical mechanical treatments of potential energy sur
faces (PES's). Here we analyze a particular method to explain its succ
ess in locating global minima on surfaces with a multiple-funnel struc
ture, where trapping in local minima with different morphologies is ex
pected. We find that a key factor in overcoming trapping is the transf
ormation applied to the PES which broadens the thermodynamic transitio
ns. The global minimum then has a significant probability of occupatio
n at temperatures where the free energy barriers between funnels are s
urmountable.