[CPMD-list] About PARRINELLO-RAHMAN NPT simulation

[Yuan Pengfei]

DEAR CPMD user:
  When I use the PARRINELLO-RAHMAN NPT keyword to do a MD simulation, I found that the simulation will reach bad results after sever hundreds steps. All the values change to NaN,do someone know why the results change to this.

the input file is like is :
&CPMD
   MOLECULAR DYNAMICS CP
   RESTART WAVEFUNCTION COORDINATES 
   TIMESTEP
    2.0
   MAXSTEP
    10000
   PARRINELLO-RAHMAN NPT
   SPLINE RANGE
     3
   NOSE IONS
    293.0D0   3000
   NOSE CELL
    293.0D0  5000
&END

&DFT
  FUNCTIONAL OLYP
&END

&SYSTEM
  ANGSTROM
  POINT GROUP
   AUTO
  STRESS TENSOR
  10.0 0.0  0.0
  0.0  10.0  0.0
  0.0  0.0  10.0
  SYMMETRY
  1
  CELL ABSOLUTE
  6.0   6.0    6.0    0.0      0.0    0.0 
  CUTOFF
  70.0
&END

&ATOMS
  .......
&END

the result is like is :

......
 NFI    EKINC    EKINH  TEMPP           EKS      ECLASSIC          EHAM         DIS     TCPU
         1  0.00032  0.00464  298.2    -112.27991    -112.24922    -112.24426   0.207E-02     0.12
         2  0.00385  0.00018  305.5    -112.27742    -112.24590    -112.24187   0.678E-02     0.11
         3  0.00928  0.00185  321.9    -112.28892    -112.25598    -112.24485   0.307E-02     0.11
         4  0.01021  0.00085  340.6    -112.28559    -112.25119    -112.24013   0.205E-02     0.10
         5  0.01226  0.00653  354.2    -112.30026    -112.26488    -112.24609   0.819E-02     0.11
......
       434  0.04326  0.02273  626.5    -112.02523    -104.89117    -104.82518   0.216E+00     0.10
       435  0.04816  0.05288  604.8    -111.99616     -22.84855     -22.74751   0.254E+00     0.11
       436  0.04886  0.05436  580.5    -112.16762    1442.74236    1442.84558   0.182E+00     0.11
       437NaN      NaN      NaN    NaN           NaN           NaN           NaN              0.09
       438NaN      NaN      NaN    NaN           NaN           NaN           NaN              0.09
       439NaN      NaN      NaN    NaN           NaN           NaN           NaN              0.10
       440NaN      NaN      NaN    NaN           NaN           NaN           NaN              0.09
       441NaN      NaN      NaN    NaN           NaN           NaN           NaN              0.08
	

Thank You
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡
 				

¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡Yuan Pengfei
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡pfyuan at ustc.edu
¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡¡2005-11-02