[CPMD-list] NaNQ on P690 & on P630

[Dr. Balasubramanian Sundaram]

Hi All,

    I use CPMD-3.7.1.

     I am trying to run a MD run of one CO_2 molecule on IBM's P690
(and also tried on P630 with identical experience). The job runs 
fine for Geometry Optimization. When I do a MD run, the job runs fine
for a few steps, and then the electron kinetic energy increases to 
large values and I get a NaNQ.

  Also note that, I do a "QUENCH BO" before the MD starts, as is
required.

   I used to run this in Parallel with a Makefile generated from the
Configure script for option, "IBM-SP4-SMP". In the Makefile, I removed
the "-qsmp=omp" option, as my machine does not have OpenMP support.
I got a NaNQ for this run.

   So, I stripped every option (such as -O3, -qtune, -qarch etc..), and 
also changed the compiler to just "xlf_r" instead of "mpxlf_r", i.e.,
basically produced a serial code. (also removed the appropriate
CPPFLAGS).
Yet, I got the NaNQ at the exact step number.

  Importantly, the input file for the job appears to be fine. I used it
to run the CPMD job on a Intel PC/IFC platform, where it runs fine for 
several thousands of steps.

 Here are some details of the P630:
 AIX 5L, v5.1, xlf v8.1, ESSL v3.3, Lapack v3.0, PWR4 CPU.

 I have tried changing the pseudopotentials also (between USPP and
MT_BLYP 
for oxygen).

    We compiled lapack ourselves. Is there something specific to be done
in
compiling lapack on IBMs? (We tried running the code with & without the
CCI
library also; Both ways produced NaNQs).

     I would very much appreciate if you can point out any mistakes that
I have
been doing. It has been a nerve-wracking week. 

I give below 3 files: (a) Relevant portion of the Makefile, (b) Input
file,
and (c) Portion of the output.

Many Thanks,

Best,
Bala
http://www.jncasr.ac.in/bala

-------------------Makefile used on
P690-------------------------------------

FFLAGS =  -qmaxmem=32768 -qtune=pwr4 -qarch=pwr4
LFLAGS = -L/export2/usr/lib -llapack -lesslsmp -llapack \
             -bbinder:/usr/lib/bind -bmaxdata:2048000000 -qarch=pwr4
$(QMMM_LIBS)
CFLAGS =
CPP = /usr/ccs/lib/cpp -P
CPPFLAGS = -D__IBM -DLAPACK -DPARALLEL=PARALLEL -DMP_LIBRARY=__MPI
-DFFT_ESSL
NOOPT_FLAG =
CC = cc
FC = mpxlf_r -c
LD = mpxlf_r
AR = /usr/bin/ar
-------------------------------------------------------------------------------
              INPUT FILE
              ^^^^^^^^^^
&CPMD
 MOLECULAR DYNAMICS
 MAXSTEP
 5000
 STORE
 10
 TIMESTEP
 5.0
 EMASS
 400.0
 NOSE IONS
 300 2000
 NOSE IONS
 0.0002 5000
 QUENCH BO
 STRUCTURE BONDS ANGLES
&END

&SYSTEM
 ANGSTROM
 CELL
 8.0 1.0 1.0 0.0 0.0 0.0
 SYMMETRY
 0
 CUTOFF
 70.0
&END

&DFT
  FUNCTIONAL BLYP
  GC-CUTOFF
  1.0D-8
&END

&ATOMS
*C_MT_GIA_BLYP KLEINMAN-BYLANDER
  LMAX=P
      1
   0.0 0.0 0.0 6 0
*O_MT_GIA_BLYP KLEINMAN-BYLANDER
  LMAX=P
   2
   -1.188 0.00 0.00 8 0
    1.188 0.00 0.00 8 0
&END
-------------------------------------------------------------------

            PARTIAL OUTPUT SHOWING THE GENERATION OF NANQ DURING MD
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

        11   .00000      .1     -37.64491     -37.64490     -37.64490   
.000    2.57
        12   .00000      .1     -37.64491     -37.64490     -37.64490   
.000    2.69
        13   .00000      .1     -37.64491     -37.64490     -37.64490   
.000    2.41
        14   .00000      .1     -37.64490     -37.64489     -37.64489   
.000    2.55
        15   .00001      .1     -37.64487     -37.64485     -37.64485   
.000    2.60
        16   .00002      .1     -37.64475     -37.64473     -37.64471   
.000    2.61
        17   .00006      .1     -37.64431     -37.64429     -37.64423   
.000    2.65
        18   .00023      .1     -37.64275     -37.64274     -37.64251   
.000    2.66
        19   .00082      .1     -37.63717     -37.63715     -37.63634   
.000    2.45
        20   .00295      .1     -37.61712     -37.61710     -37.61415   
.000    2.33

 RESTART INFORMATION WRITTEN ON FILE                  ./RESTART.1
        21   .01063      .1     -37.54493     -37.54491     -37.53428   
.000    2.34
        22   .03834      .1     -37.28448     -37.28447     -37.24613   
.000    2.37
        23   .13800      .0     -36.34269     -36.34267     -36.20467   
.000    2.79
        24   .49550      .0     -32.90880     -32.90878     -32.41328   
.000    3.03
        25  1.73934    NaNQ     -19.91875          NaNQ          NaNQ   
.000    2.66
        26     NaNQ    NaNQ          NaNQ          NaNQ          NaNQ   
NaNQ    2.39