[CPMD-list] Energy conservation

[Nick Cooper]

Hello all,

I am simulating covalent materials at relatively high temperatures (3500K)
and I have noticed that the conserved quantity in a canonical ensemble is
monotonically decreasing, though admittedly the absolute change is small.
I have tried decreasing the timestep (from 3au down to 1au) but all this
does is decrease the gradient of the drop in energy. The systems I am
looking at have significant metallic character at this temperature, so I
have used a Nose-Hoover themostat for the ions and wavefunctions.

The monotonic nature is what has me worried- am I just being paranoid?

Any advice you can offer would be gratefully received.

Yours sincerely,

Nicholas Cooper

PhD Student,
The University of Sydney,
NSW 2006 AUSTRALIA