[CPMD-list] NAN trajectory for 32 water simulation

bala at jncasr.ac.in bala at jncasr.ac.in
Tue Dec 11 04:06:01 UTC 2007


Dear Chang,
   I assume that you have performed a wavefunction optimization prior to
this MD run.
   Your timestep (7 a.u.) is somewhat on the high side; however the EMASS
too is large, so this timestep may be ok. A timestep of 4 a.u. or 5
a.u. and  a EMASS of 400 or 500 are conservative numbers.

   More crucially, you may want to try using the ISOTOPE keyword and
deuterate the hydrogens.

   Also, as Axel has pointed out many times on this list, try not to
thermostat the electrons, unless it is absolutely essential. I don't
think that it is necessary for liquid water.

best wishes,
bala


> Dear CPMD users,
>
> I'm running CPMD with 32 water for a test case.
> I get NAN in TRAJEC.xyz for my water simulation. I found some posting
> about NAN problem in the CPMD mailing-list. My case is little different.
> Now I'm trying to follow published work: JCP 120, 300 (2004). Since the
> paper didn't specify temperature coupling, I took Nose-hoover parameters
> from JPCB 108, 12990 (2004).
> I don't know why I'm getting NAN.
>
> Please help me if anyone knows.  Thanks a lot in advance!
>
> Chang
> Here is my input file.
>
> &CPMD
>   MOLECULAR DYNAMICS CP
>   RESTART WAVEFUNCTION COORDINATES LATEST
>   TRAJECTORY XYZ
>   TEMPERATURE
>   300
>   TIMESTEP
>   7.0
>   MAXSTEP
>   100
>   EMASS
>    760
>   NOSE IONS
>   298 2000
>   NOSE ELECTRONS
>   0.04 10000
> &END
>
> &DFT
>   FUNCTIONAL BLYP
> &END
>
> &SYSTEM
>   SYMMETRY
>   1
>   CELL
>   18.6251  1.0  1.0  0  0  0
>   CUTOFF
>   80.0
> &END
>
> &ATOMS
> *O_GO_BLYP.psp  KLEINMAN-BYLANDER
>    LMAX=P
>  32
>   0.3590     6.9542     12.2265
>   2.8157     13.2848     13.5493
>   12.9446     0.4913     12.5667
>   11.4517     18.2170     2.3244
>   11.3006     13.7761     5.1023
>   0.0945     7.7479     4.8377
>   1.0393     13.2470     8.1069
>   10.3935     3.7039     16.7241
>   7.2188     13.2281     9.0707
>   17.4233     9.5053     16.9886
>   10.1856     1.2094     9.6754
>   10.6014     4.1952     3.0425
>   13.3226     1.2094     6.9542
>   10.6958     10.1478     16.3461
>   4.2141     9.9211     5.1967
>   13.8328     11.9809     1.4740
>   5.8015     1.1905     11.6785
>   0.6992     14.4753     18.2548
>   6.0282     15.3068     17.9335
>   6.4062     9.6187     0.3779
>   15.4013     10.8092     6.1416
>   8.9384     9.4486     3.6094
>   5.9715     16.1572     5.8393
>   1.5685     5.1401     0.6803
>   17.0642     1.6252     2.5133
>   4.9700     6.1605     13.6060
>   17.3099     17.1965     5.4991
>   1.3606     3.1369     6.0093
>   4.5164     6.1416     8.4849
>   11.2250     14.0785     12.3210
>   16.2327     18.0658     16.2705
>   8.0880     8.0124     9.8266
> *H_MT_BLYP.psp
>    LMAX=S
>   64
>   -1.1905     7.7668     12.9635
>   -0.1701     5.5747     11.0360
>   3.8928     14.7588     13.0769
>   1.6819     13.7761     14.9855
>   14.2485     0.1890     13.8895
>   11.5651     1.5685     13.2848
>   11.5840     19.8043     1.3039
>   12.3210     18.4626     3.9873
>   11.7541     15.0800     3.8172
>   9.8266     14.3997     6.1227
>   -1.3606     8.3904     5.8582
>   -0.5480     6.7841     3.3448
>   1.5307     13.1714     9.9211
>   -0.5669     12.2832     7.8424
>   10.2990     3.6094     18.6138
>   10.4313     5.5180     16.1761
>   8.0691     11.5273     9.0140
>   5.4424     13.0202     9.6943
>   16.9508     9.3352     15.1745
>   18.3303     7.9557     17.5745
>   8.6549     1.2283     10.7714
>   10.2423     2.7779     8.6360
>   11.3195     2.6078     3.7417
>   8.9384     4.5542     3.8739
>   13.0580     1.3417     8.8250
>   14.9099     0.2457     6.6140
>   10.9226     11.3950     14.9477
>   11.5651     10.7903     17.9146
>   4.4598     8.3337     6.2172
>   3.6661     11.3195     6.3306
>   14.9477     11.4895     0.0378
>   13.3037     13.7950     1.2661
>   5.5936     2.9669     12.3021
>   5.7070     0.0000     13.1336
>   0.9827     14.8721     20.0689
>   0.1323     12.6801     18.0847
>   7.7857     15.9871     18.0280
>   5.9148     13.7005     18.9162
>   5.4235     8.0502     0.0567
>   7.8613     9.7132     -0.8315
>   15.5335     9.1274     5.2723
>   13.6249     11.4517     5.9904
>   10.0911     10.9604     3.6850
>   7.1432     10.0344     3.7417
>   4.3464     15.5713     6.6329
>   5.8959     15.8926     3.9684
>   1.4740     5.1212     2.5700
>   0.0000     4.3653     -0.0378
>   18.0280     1.6441     0.8882
>   18.1225     0.8315     3.8550
>   3.4771     7.1243     12.9635
>   4.7999     5.8770     15.4580
>   18.5004     17.9146     4.2141
>   18.0658     15.6280     6.2361
>   1.0393     4.7054     4.9889
>   3.0614     2.4377     5.5936
>   5.7448     4.7432     8.2770
>   4.8944     7.0865     10.0722
>   12.1698     15.6847     11.9620
>   9.5620     14.1163     11.4139
>   17.2532     16.7619     17.1776
>   15.6280     19.3697     17.5178
>   8.6549     6.6518     8.6549
>   7.3510     7.2565     11.3950
> &END
>
>
> Chang Yeon Won
> -------------------------------------------------------------------------
> Grad. Res. Asst. (Ph.D Candidate)
> Computational MEMS/Nano Lab
> 3213 Beckman Institute
> University of Illinois at Urbana-Champaign
> 405 N. Mathews Avenue
> Urbana, IL 61801                            Office (217)244-1964
> -------------------------------------------------------------------------
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