[CPMD-list] cp molecular dynamic

[Axel Kohlmeyer]

On Mon, 23 Jul 2007, kdong wrote:

KD> Dear every cpmd users,

KD>   After wavefunction optimization, I attempt to execute cp-molecular
KD> dynamic, the input is as follows,

[...]

KD> My system is liquid, the melting point is 350.0k, so the tempature is 350.0. 
KD> Because total time was 2ps, and the maxstep is 2000, so the timestep is 50.0.
KD> But the results was showed "NaN" for forces and different energies.
KD> who can tell me the reasons?

your input parameters are wrong! the time step is 
determined by the fastest motion of your system and
not what you want it to be. 50 a.u. is _huge_ and 
even with a very large fictitious mass of 1100.0 a.u. 
the cp-dynamics will diverge quickly. 

cheers,
   axel.

KD> 
KD> Best regards
KD> k.dong
KD> 
KD> 
KD>  
KD>   2007-07-23 21:42:25 
KD> 
KD> 
KD> 
KD> K. Dong    
KD> Institute of Process Engineering
KD> Chinese Academy of Sciences (CAS)
KD> Beijing 100080, China
KD> Tel: 86-10-62550850
KD> Mobile: 13811865926
KD> Email: dongkun at home.ipe.ac.cn and kdong_bj at sina.com  
KD> 

-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
   Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
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