Dave,
Thanks for looking at this. I'd be glad to run additional tests if needed.
Istvan
Quoting case <case.biomaps.rutgers.edu>:
> Istvan, Ross, Andreas, others:
>
> It turns out that the default behavior for sqm has gradients that are not
> accurate enough. If you set "grms_tol=0.0001, tight_p_conv=1,
> scfconv=1.d-10," in the namelist input for sqm, you then get
> good behavior
> with the TCNG minimizer, as expected, and as we see with MM gradients (which
> are essentially exact.)
>
> I can/will change antechamber to set stricter parameters to get AM1-BCC
> charges...we'll see if this helps reduce the dependence on compiler.
>
> But this also leaves open the question of what the defaults should be for
> sqm as used in QM/MM molecular dynamics. I don't know how much testing was
> done, but it is of concern that the default for tight_p_conv is zero, since
> Istvan's analyis shows that this is dangerous, at least for minimization.
> I'm not changing things right now, since that would probably involve updating
> every one of 100 or so QM/MM test cases (sigh), but it is something that
> I'd like to get comments on.
>
> ...thx...dac
>
>
> _______________________________________________
> AMBER-Developers mailing list
> AMBER-Developers.ambermd.org
> http://lists.ambermd.org/mailman/listinfo/amber-developers
>
_______________________________________________
AMBER-Developers mailing list
AMBER-Developers.ambermd.org
http://lists.ambermd.org/mailman/listinfo/amber-developers
Received on Thu Dec 17 2009 - 12:00:04 PST
