[CPMD-list] Some questions about MD in CPMD

[c00ycl00]

Dear all,

         I am trying some exercises of CPMD.  But when I
do the exercise 2.4 of the CECAM tutorial ( MD simulation
for NaCl), I got some errors in the TRAJECTORY and 
ENERGIES output file.  I use the Born-Oppenheimer
MD with EMASS of 1200 a.u. and timestep of 10 a.u..
The program can stop normally and there is no any
error message in the log file.  But in the TRAJECTORY
file, all of the position and gradient of the unconstrianed Na
atom appear NaNQ sign ( but the finial results of the position
and gradient in log file is normal).  I also use the Car-Parrinello
MD with EMASS of 1200 a.u. and timestep of 5 a.u., 10 a.u.,
50 a.u., the TRAJECTORIES and ENERGIES files are normal.
But when I use the timestep of 100 a.u., the TRAJECTORIES
and ENERGIES appear NaNQ again.  Can anyone tell me
what's wrong in this simulation?  Thank you for your help.

Best regards,
Yung-Chiang Lan

The input file I used is listed below:
-----------------------------------------------------------------
&CPMD
  RESTART WAVEFUNCTION COORDINATES LATEST
  MOLECULAR DYNAMICS BO
  MAXSTEP
  3310
  TIMESTEP
  10.0
  EMASS
  1200
  TRAJECTORY SAMPLE
  1
  STORE
  500
&END

&DFT
  NEWCODE
  FUNCTIONAL BLYP
  GC-CUTOFF
  0.1E-04
&END

&SYSTEM
  ANGSTROMS
  SYMMETRY
  1
  CELL
  5.6352  1.0  1.0  0  0  0
  CUTOFF
  30.0
&END

&ATOMS
*Na_SG_BLYP KLEINMAN-BYLANDER
 LMAX=P
 4
 2.8176 2.8176 2.6176
 2.8176 0.0 0.0
 0.0 2.8176 0.0
 0.0 0.0 2.8176

*Cl_SG_BLYP KLEINMAN-BYLANDER
 LMAX=P
 4
 0.0 0.0 0.0
 2.8176 2.8176 0.0
 2.8176 0.0 2.8176
 0.0 2.8176 2.8176

 CONSTRAINTS
 FIX ATOMS
  7
  2 3 4 5 6 7 8
 END CONSTRAINTS

&END
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