| 1:11:06 PM PDT - Thu, Apr 12th 2012 |
|
Seems there is a tug of war going on with the internal coordinates. I got the calculation to converge using:
symmetry noautosym noautoz
driver
tight
maxiter 100
end
The latter forces the use of cartesians. Still takes a while to converge, but it does.
Bert
Quote:Richard Apr 10th 9:51 pmSorry if I haven't made myself clear, I mean geometric convergence. If I specify 'tight' it never converges (geometrically).
That's the problem.
Specifying 'tight', Gmax Grms etc. never quite all fall below the thresholds, up to a large number of steps.
Trying to increase precision in various ways, thresh, eprec, energy convergence, larger grid (the original post showed one attempt) so far hasn't worked, although without any experience of nwchem's optimizer I'm just guessing here...
Richard
Quote:Bert Apr 10th 8:49 pmWhat is the goal of the tighter convergence? If your goal is to converge the geometry further, you should try setting:
driver
tight
maxiter 500
end
Bert |