[CPMD-list] convergence of metadynamics runs?

[Ali Hassanali]

Dear CPMD Users,

I am curious to know if anyone can shed some light on how to determine if 
a metadynamics simulation has converged or not. To paraphrase that, when 
does one stop a metadynamics simulations. The literature I have read 
indicates that it is critical to stop it at the right point otherwise the 
system might get into exploring unphysical minima. Is anyone aware of any 
quantitative measure to determine when/if the free energy surface has 
converged or not?

I can think of several things:

i) A recrossing back into an "old minimum" a good indication of 
convergence (or close to convergence) ?

ii) Evaluating error bars in the free energy value from the hills along 
the trajectory and along bins and checking to see that they remain 
reasonably constant over blocks?

I'd be happy to hear other insights or opinions.

Ali