CCL: GAMESS:SCF-Problem with DFT



 Sent to CCL by: "Rudolf Herrmann"
 [rudolf.herrmann#,#physik.uni-augsburg.de]
 Dear Gustavo,
 thank you for your suggestions. I played some time around with the
 options, and finally got it work.
 >
 > Sent to CCL by: Gustavo Mercier [gamercier::yahoo.com]
 > Hi!
 >
 > Several points:
 >
 > 1. Normally if you go with DIIS then Damping and Vshifting is turned off.
 > Look at the REF.doc in the Gamess distribution where they give hints
 > for helping in convergence.
 OK I know that. Damping and Vshifting is there only in case DIIS does not
 start immediately.
 > They also make a suggestion in the INPUT.doc
 > under the SCF namelist where they suggest using ETHRESH and
 > SWDIIS. I do not recommend the SWDIIS option because what it does is
 > switch from DIIS to the second order method (SOSCF), and this has not
 > worked out as well for me.
 >
 That's precisely what I found as well: SOSCF is much more sensitive and
 crashes easier than DIIS.
 > 2. Set ETHRESH (option under SCF) to a large value like 2E+0. This will
 > make DIIS kick in early, and should stay on pretty much all the time.
 >
 That was precisely what worked! Although DIIS was switched off again once,
 SCF did recover after ca. 30 crazy steps and finally converged.
 > 3. Another thing is the number of points used for computing the functional
 > integrals. This is done numerically and is controled by the DFT namelist.
 > The program uses a low number of points in the early iterations, and then
 > switches to the full grid. I find that I have to start the full grid
 > earlier.
 That was not successful in my case.
 > I've also had to use larger than default values and go up to 434
 > and 590. I do work on Mn coordination complexes and they seem to be fairly
 > soft with a fairly flat potential energy curve. Read under REF.doc details
 > about the grids and expected accuracy in the energy gradients.
 >
 Together with ETHRSH=2.0 this works as well but does not really improve
 the calculation.
 > I would also recommend doing the geometry optimization with delocalized
 > coordinates:
 >
 > $ZMAT DELOC=.T. AUTO=.T. $END
 >
 > you also need to specify the number of variables in the $CONTRL namelist
 > using (I believe) NZVAR=3*N-6 where N is the number of atoms.
 > This will reduce the number of iterations and I find that it makes for a
 > smarter optimization.
 Did not work (I tried that with isomers of this compound earlier as well).
 The program crashes with
 BAD DELOCALIZED COORDINATES GENERATED !!!
 >
 > On another note... if you intend to do thermochemistry, I've found that
 > the 'approximate' hessian kicked out at the end of the geometry
 > optimization is not bad. For DFT the second derivatives are computed using
 > numerical methods from (mostly) analytic gradients. Seems tha the
 > augmented hessian methods that are used for default in geometry
 > optimizations do a good job at getting the hessian ok, or at least as good
 > as the default one-point numerical differentiation formula.
 >
 Thanks a lot for this hint. Actually I do not need thermochemistry for the
 moment, but that could be very helpful for the future.
 > Hope this helps!
 >
 > --
 > Gustavo A. Mercier, Jr., MD, PhD
 > gamercier=yahoo.com
 > Gustavo.Mercier=bmc.org
 > gumercie=bu.edu
 > 617-414-6440
 >
 Thank you again
 Yours
 Rudolf.
 >
 >
 >
 > ----- Original Message ----
 >> From: Rudolf Herrmann rudolf.herrmann__physik.uni-augsburg.de
 >> <owner-chemistryÌl.net>
 >> To: "Mercier, Gustavo, " <gamercier=yahoo.com>
 >> Sent: Mon, December 21, 2009 6:42:44 AM
 >> Subject: CCL: GAMESS:SCF-Problem with DFT
 >>
 >>
 >> Sent to CCL by: "Rudolf Herrmann"
 >> [rudolf.herrmann:+:physik.uni-augsburg.de]
 >> Hello all,
 >> I'm using GAMESS(US), rev. R3 from Jan 12, 2009. I encountered a
 problem
 >> in obtaining SCF with DFT. Part of the input:
 >>
 >> $CONTRL SCFTYP=UHF MULT=2 RUNTYP=Optimize COORD=unique INTTYP=HONDO
 $END
 >> $CONTRL DFTTYP=PBE0  MAXIT=200 ICHARG=0  ECP=SBKJC  $END
 >> $SYSTEM TIMLIM=80000 MEMORY=80000000 $END
 >> $SCF DIRSCF=.T. DAMP=.T. SHIFT=.T. DIIS=.T. SOSCF=.F.  $END
 >> $BASIS  GBASIS=SBKJC  $END
 >> $STATPT OPTTOL=0.0001 NSTEP=200  $END
 >> $GUESS  GUESS=HUCKEL  $END
 >> $DATA
 >> 4*Fuenfring - Phthalo  cctt als Cu-Komplex UHF
 >> C1
 >> C  6.0  -5.216897    -0.910406  -10.919197
 >> .......  (many atoms)
 >>
 >> And that is the result of the first SCF calculation:
 >>
 >>
 >>
 >>                               NONZERO
 >>
 >>
 >>
 >>
 >> BLOCKS
 >> ITER EX      TOTAL ENERGY        E CHANGE  DENSITY CHANGE    DIIS ERROR
 >>   VIR. SHIFT      DAMPING        INTEGRALS    SKIPPED
 >>   1  0    -1036.5378101022 -1036.5378101022  1.230919053  0.821519137
 >>   0.000000000    1.000000000    6231081460  193615138
 >>           * * *  INITIATING DIIS PROCEDURE  * * *
 >>   2  1    -1041.6461370603    -5.1083269581  11.464555047  0.402615779
 >>   0.000000000    1.000000000    6236128017  193099683
 >>   3  2    -1002.7358262561    38.9103108042  11.474994560  1.302218004
 >>   0.000000000    1.000000000    6241249413  191679251
 >>   4  3    -1041.8568160646  -39.1209898086  0.195994971  0.402579497
 >>   0.000000000    1.000000000    6237469221  191939968
 >>   5  4    -1042.3054537170    -0.4486376523  0.226115870  0.343346341
 >>   0.000000000    1.000000000    6057043846  201451242
 >>   6  5    -1042.6171017767    -0.3116480597  0.279322397  0.266341119
 >>   0.000000000    1.000000000    6061097833  201455155
 >>   7  6    -1042.9966679031    -0.3795661264  0.106460306  0.081821934
 >>   0.000000000    1.000000000    6077977863  201147673
 >>   8  7    -1043.0591297051    -0.0624618020  0.046857045  0.011477052
 >>   0.000000000    1.000000000    5989046608  202974307
 >>   9  8    -1043.0669450821    -0.0078153770  0.011381853  0.005948448
 >>   0.000000000    1.000000000    5736168713  207005748
 >>   10  9    -1043.0697884590    -0.0028433770  0.013485505  0.004417363
 >>   0.000000000    1.000000000    5475629752  210127430
 >>   11 10    -1043.0723408038    -0.0025523448  0.017067266  0.003869563
 >>   0.000000000    1.000000000    5458702402  210313186
 >>   12 11    -1043.0751463423    -0.0028055385  0.014434645  0.003675831
 >>   0.000000000    1.000000000    5453595333  210460303
 >>   13 12    -1043.0777030610    -0.0025567187  0.019791837  0.003849315
 >>   0.000000000    1.000000000    5397573182  211084337
 >>   14 13    -1043.0813673308    -0.0036642698  0.004903916  0.004281832
 >>   0.000000000    1.000000000    5491928111  210122347
 >> CONVERGED TO SWOFF, SO DFT CALCULATION IS NOW SWITCHED ON.
 >>           * * *  INITIATING DIIS PROCEDURE  * * *
 >>   15 14    -1058.1568375748  -15.0754702440  1.625183076  0.052558260
 >>   6225076316  194161508
 >>   16 15    -1056.2538409178    1.9029966571  0.866868728  0.796456193
 >>   6203667374  195873448
 >>   17 16    -1058.5031727428    -2.2493318250  0.157468336  0.035593489
 >>   6097769151  200991564
 >>   18 17    -1058.2872778511    0.2158948917  0.070399380  0.134520819
 >>   6058543947  201342138
 >>   19 18    -1058.5442781186    -0.2570002675  0.113766853  0.013742123
 >>   5927217989  204237218
 >>   20 19    -1058.5522842356    -0.0080061170  0.023549798  0.007512045
 >>   5840741652  205391057
 >>   21 20    -1058.5530282008    -0.0007439652  0.017420717  0.010226036
 >>   5670929315  208075365
 >>   22 21    -1058.5559993807    -0.0029711799  0.047523393  0.009589402
 >>   5564367770  209481859
 >>   23 22    -1058.5585808178    -0.0025814371  0.029346400  0.024600824
 >>   5707543406  207871809
 >>   24 23    -1058.5575623133    0.0010185045  0.013103014  0.017673475
 >>   5514532287  210353312
 >> NEXT ENERGY RISES: SWITCHING DIIS OFF FOR  5 ITERS, NEW ETHRSH=
 1.59E-02
 >>   25 24    -1058.5566503140    0.0009119993  0.065560927  0.026774000
 >>   5383825524  211393480
 >>   26 25    -1058.5245291667    0.0321211473  0.955346110  0.097075114
 >>   5824682851  206204169
 >>   27 26    -1045.4354021475    13.0891270192  19.549841437  1.414811739
 >>   6176465140  198256544
 >>   28 27    -820.5152084492  224.9201936983 183.173769694  2.570654172
 >>   6246989834  190654722
 >>   29 28      615.6159645678  1436.13117301703000.606626971  2.010533226
 >>   6254865291  185798793
 >>   30 29    1752.6067873608  1136.99082279303001.172518613  10.378186893
 >>   6256392203  177999716
 >>   31 30    1765.6511795332    13.04439217243095.179109875  2.823919783
 >>   6256414149  176971112
 >>   32 31    2820.6124946084  1054.96131507523095.984312651  2.819419434
 >>   6256313973  177970697
 >>   33 32    2012.2921032636  -808.32039134473958.491129374  3.341335928
 >>   6256340795  177974590
 >>   34 33    3111.0312907781  1098.73918751453958.190267766  2.732484925
 >>   6256322037  177808512
 >>   35 34    2059.9131221528 -1051.11816862534124.537686577  3.295129177
 >>   6256330123  177699772
 >> ....... and so on (oscillates).
 >>
 >> My question is: Everything seems reasonable until the program's
 decision
 >> to turn off DIIS for five iterations. How can I switch off this
 >> behaviour?
 >> I did not find any hint in the manual (maybe I have simply overlooked
 >> it).
 >>
 >> Thanks a lot for suggestions.
 >>
 >> Merry Christmas and lots of successful calculations in the New Year!
 >>
 >> R. Herrmann.
 >>
 >> --
 >> Dr. Rudolf Herrmann
 >> Institut für Physik
 >> Universität Augsburg
 >> Universitätsstr. 1
 >> D-86159 Augsburg>> the strange characters on the top line to the
 = sign. You can also>>
 >> E-mail to subscribers: CHEMISTRYÌl.net or use:>
 >
 >