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["matthieu verstraete" <matthieu.jean.verstraete@gmail.com>]

This is normal, in any minimization procedure with multiple local minima and/or a complex energy landscape (contrasting with the very simple electronic DFT case for non spin polarized electrons with only one minimum). The Broyden overshoots in its search for the minimum, and the force/stess increases. As long as things stay manageable (ie you do not exit the well of attraction of the minimum or explode the system) the algorithm should return to a better minimum and converge anyway.

Matthieu

On Sun, Jan 4, 2009 at 8:32 PM, Julie Smart <smart.julie@rocketmail.com> wrote:

Hello,

I have taken up TM LDA pseudo potential in one run and in the other for the same input I took GGA FHI.

For both of them, the run converged, but surprisingly during the run in both of them, at some broyden/MD steps, I encountered that the force/stress is higher than the previous step.

Why does it happen and how could we solve this problem?

-- 
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Dr. Matthieu Verstraete

European Theoretical Spectroscopy Facility (ETSF) 
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