[Pw_forum] CP breakdown for long simulations?

[Brandon Wood]

Hi all,

I'm running the CVS version of CP, and I'm wondering if anyone else has 
come across this problem.  After ~10,000-15,000 timesteps of good data 
for a well-behaved, insulating system, the total integrated electronic 
charge density is suddenly no longer conserved and begins to fluctuate. 
  As a result, the total energy drops rapidly and the simulation goes 
haywire.

It seems like it is due to compounding of small numerical errors.  Could 
there be a problem with the orthonormalization scheme that carries over 
from timestep to timestep but only manifests itself after sufficient 
time, for instance?

Thanks,
Brandon

-------------------------------------
Brandon C. Wood
Quasiamore Group
Department of Materials Science
Massachusetts Institute of Technology
Office: 13-4078
Email: brandonw at mit.edu
Phone: (617) 452-2455
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