[CPMD-list] serial and parallel gradients differ

[Robert Williams]

Dear CPMDers,

Results from my serial and parallel optimizations
using cpmd3.9.1 differ significantly, starting from
identical input files (attached) using tight
convergence criteria.  Below are parts
of the final results for serial and parallel runs
on P4 linux systems.  Of particular interest to me,
why are the gradients zero in the serial results,
and near the GNORM in the parallel results?
This is reflected also in the GEOMETRY.xyz files.
(Compile time optimizations for each version differ
a little.)

Serial   3.9.1:
  *** TOTAL STEP NR.  9999           GEOMETRY STEP NR.   2284  ***
  *** GNMAX=  1.182878E-03 [5.35E-05]     ETOT=   -189.032981  ***
  *** GNORM=  2.870398E-04               DETOT=     1.005E-09  ***
  *** CNSTR=  0.000000E+00                TCPU=         80.58  ***
...
  =              END OF GEOMETRY OPTIMIZATION                    =
  *                        FINAL RESULTS                         *
...
    ATOM          COORDINATES            GRADIENTS (-FORCES)
    1  O  5.1224  2.8573  3.3944   0.000E+00  0.000E+00  0.000E+00
    2  O  4.1231  8.7555 10.3710   0.000E+00  0.000E+00  0.000E+00
    3  O 14.3880  2.7858  3.3105   0.000E+00  0.000E+00  0.000E+00
    4  O 13.4023  8.7048 10.1629   0.000E+00  0.000E+00  0.000E+00
..................................................................

Parallel 3.9.1:
  *** TOTAL STEP NR.  6604           GEOMETRY STEP NR.   1400  ***
  *** GNMAX=  1.825868E-03 [8.65E-09]     ETOT=   -189.032988  ***
  *** GNORM=  4.655294E-04               DETOT=    -2.749E-10  ***
  *** CNSTR=  0.000000E+00                TCPU=         18.64  ***
...
  =              END OF GEOMETRY OPTIMIZATION                    =
  *                        FINAL RESULTS                         *
...
    ATOM          COORDINATES            GRADIENTS (-FORCES)
    1  O  5.1271  2.8813  3.4124  -7.567E-04  9.170E-05 -4.731E-04
    2  O  4.1229  8.6424 10.2943   6.352E-04 -9.080E-06  1.336E-04
    3  O 14.4179  2.8784  3.3640   1.826E-03 -1.309E-04  3.528E-04
    4  O 13.3743  8.6440 10.2220  -1.175E-03 -2.027E-04  2.011E-04
..................................................................


Bob

-- 
Dr. Robert Williams
Department of Biomedical Informatics
Uniformed Services University
301-295-3568
-------------- next part --------------
An embedded and charset-unspecified text was scrubbed...
Name: nma-novdw-2k-nosym-opt.inp
Url: http://cpmd.org/pipermail/cpmd-list/attachments/20050326/431e332c/attachment.cc