[CPMD-list] Nose thermostat

[Walter Langel]

Hi,

I have a question concerning the energies in the cpmd output files for 
molecular dynamics with Nose thermostat:

Without Nose thermostat, ECLASSIC is simply given as sum of potential 
and kinetic ion energies, EKS+EKION, and the printed out temperature 
TEMPP is related to EKION by
EKION=N kb TEMPP/2 , where N is the number of unconstrainend degrees of 
freedom. (As written in the manual).

With Nose thermostat, ECLASSIC-EKS fluctuates very strongly and can take 
negative values (???), even if the printed out value for TEMPP is fairly 
constant around 300 K.
Especially, ECLASSIC-EKS is most of the time completely different from 
the value of EKION, calculated from the value for TEMPP given by the 
program.

Can anyone tell me, what the meaning of ECLASSIC is when unsing the Nose 
thermostat, and how it is calculated then.

Thanks

Walter Langel

-- 
Prof. Dr. Walter Langel
Institut fuer Biochemie
Universitaet Greifswald
Felix-Hausdorff-Straße 4
17487 Greifswald
Germany
Tel +49 3834 86 4423
Fax +49 3834 86 4475
http://www.chemie.uni-greifswald.de/~plasma