[CPMD-list] convergence problem on iron porphyrin

Axel Kohlmeyer akohlmey at vitae.cmm.upenn.edu
Fri Jul 28 23:16:26 CEST 2006 

On 7/28/06, Yong Zhang <zhangymall11 at gmail.com> wrote:
>
>  It is working now. Thanks a lot.
>  I tried both VDB pp and MT pp, both work. So I guess the "LOC=S" for Fe is
> the point.

LOC=S is ignored for VDB. but for the Fe-MT potential essential,
so you don't have ghost states. PCG and/or PCG MINIMIZE is
the ticket for systems with tricky electron structures, which is
truely the case here.



>  By the way, do you have any special reason for using VDB? What is the
> difference between these PPs? Sorry if this is a naive question. I am a very
> beginner of CMPD. :-p

in that case, you should probably start with a simpler system.
there are references for both types of pseudopotentials in the manual.

VDB pseudopotentials need a (much) lower plane wave energy cutoff,
due to not releasing the norm-conservation constraint on the pseudopotential.

that has several implications, especially with the VDB implementation in CPMD.
since CPMD does not have a working dual grid for the uspps, you have
to crank up the density cutoff (best by using DUAL with a value of 5.0
of even 6.0)
so you get consistend DFT results and less problems with placing the
augmentation charges on the grid). also, apart from basic operations like
MD, geometry optimization, constraints, many advanced features in CPMD
do not work with ultra-soft pseudopotentials. in the case of iron, however,
the uspps should give a 'better structure' than the MT potential, provided
you take care of the other technical issues.

finally a word of caution. for the kind of system you are dealing with
certain configurations can be quite tricky and DFT may not always
give accurate results. please have a look at, e.g., page 18 of
http://www.vlab.msi.umn.edu/events/download/LDA+U.pdf
this is done with a different code, and there are other attempts
to solve this DFT related problem as well, but you should check
your results carefully.

cheers,
   axel.

>
>  Yong
>
> On 7/28/06, Pradip Kumar Biswas <p.biswas at csuohio.edu> wrote:
> > Hi,
> >
> > I had a similar problem with convergence; PCG minimize helped. However,
> > this is to mention that I used VDB pp with a w.fn cutoff of 25 Ry, dual
> > 5.0 and for iron I use LMAX=D  LOCAL=S.
> >
> > pb.
>
>
> On Jul 28, 2006, at 2:05 PM, Yong Zhang wrote:
>
> > Hello CPMDers,
> >
> >  I am trying to run some simulation on a Fe-porphyrin complex. The
> > wavefunction optimation did not tend to converge at all. I took an
> > optimized structure from MM calculation as the initial input. The
> > triplet was reported before as the stable state of this complex and
> > singlet and quintet are also possible. I tried all the three states
> > but the results are similar.
> >
> >  The input file is like below.
> >  =============
> >  &INFO
> >  isolated porphyrin
> >  &END
> >
> >  &CPMD
> >   OPTIMIZE WAVEFUNCTION
> >   CONVERGENCE
> >   1.0e-5 1.0e-4
> >   LSD
> >  &END
> >
> >  &SYSTEM
> >   ANGSTROM
> >   MULTIPLICITY
> >   3
> >   SYMMETRY
> >   0
> >   CELL
> >   20.0 1.0 1.0 0 0 0
> >   CUTOFF
> >   120.0
> >  &END
> >
>  >  &DFT
> >   NEWCODE
> >   FUNCTIONAL BLYP
> >   GC-CUTOFF
> >   5.0e-6
> >  &END
> >
> >  &ATOMS
> >
> >  *H_MT_BLYP.psp KLEINMAN-BYLANDER
> >   LMAX=S
> >   12
> >   3.31669 -2.94334 -.16809
> >   2.93762 3.31304 -.05977
> >   -3.31384 2.94309 .22042
> >   -2.92849 -3.31383 .22766
> >   4.90231 1.61056 .04513
> >   5.06326 -1.01897 -.00553
> >   1.02859 5.04983 .27002
> >   -1.59946 4.89625 .38278
> >   -5.03348 1.01638 .55312
> >   -4.86935 -1.61344 .56109
> >   -.99586 -5.05269 .33204
> >   1.62901 -4.89882 .16066
> >
> >  *C_MT_BLYP.psp KLEINMAN-BYLANDER
> >   LMAX=P
> >   20
> >   2.81762 -.90741 -.30078
> >   4.15831 -.42048 -.10975
> >   4.07679 .91069 -.08405
> >   2.68646 1.23777 -.26039
> >   .89704 2.82649 -.15632
> >   .42262 4.15497 .12858
> >   -.90781 4.07726 .18562
> >   -1.24684 2.70101 -.06341
> >   -2.83315 .90877 .01509
> >   -4.14547 .41936 .34573
> >   -4.06234 -.91195 .34981
> >   -2.69949 -1.23663 .02068
> >   -.91015 - 2.82534 -.08494
> >   -.40832 -4.15621 .13424
> >   .92048 -4.07836 .04743
> >   1.23122 -2.69964 -.22383
> >   2.50103 -2.22388 -.22696
> >   2.21409 2.50419 -.15282
> >   -2.50975 2.22465 .06664
>  >   -2.21889 -2.50376 .06438
> >
> >  *N_MT_BLYP.psp KLEINMAN-BYLANDER
> >   LMAX=P
> >   4
> >   1.89556 .11563 -.42853
> >   -.13402 1.91752 -.31014
> >   -1.93090 -.11253 -.22157
> >   .09862 - 1.91442 -.34101
> >
> >  *Fe_MT_BLYP_NLCC.psp KLEINMAN-BYLANDER
> >   LMAX=d
> >   1
> >   -.04966 .00435 -.91339
> >
> >  &END
> >  ===================
> >
> >  Here is part of the output file, the full output file is in the
> > attachment.
> >  ===================
> >  DEGREES OF FREEDOM FOR SYSTEM: 108
> >
> >  CPU TIME FOR WAVEFUNCTION INITIALIZATION: 691.99 SECONDS
> >  *** RWFOPT| THE NEW SIZE OF THE PROGRAM IS 7276372 KBytes ***
> >   EWALD| SUM IN REAL SPACE OVER 1* 1* 1 CELLS
> >
> >  TOTAL INTEGRATED ELECTRONIC DENSITY
> >   IN G-SPACE = 120.000000
> >   IN R-SPACE = 120.000000
> >  TOTAL INTEGRATED ABSOLUTE VALUE OF SPIN DENSITY 2.000000
> >
> >  (K+E1+L+N+X) TOTAL ENERGY = 106186.37660532 A.U.
> >  (K) KINETIC ENERGY = 170.36965540 A.U.
> >  (E1=A-S+R) ELECTROSTATIC ENERGY = 8.41306493 A.U.
> >  (S) ESELF = 164.89614257 A.U.
>  >  (R) ESR = 7.57734610 A.U.
> >  (L) LOCAL PSEUDOPOTENTIAL ENERGY = 106048.23117170 A.U.
> >  (N) N-L PSEUDOPOTENTIAL ENERGY = 19.39264557 A.U.
> >  (X) EXCHANGE-CORRELATION ENERGY = -60.02993229 A.U.
> >   GRADIENT CORRECTION ENERGY = - 3.00174758 A.U.
> >
> >  NFI GEMAX CNORM ETOT DETOT TCPU
> >   1 5.789E+00 1.383E-01 106186.376605 0.000E+00 657.40
> >   2 8.686E+00 1.025E-01 97560.262676 -8.626E+03 625.52
> >   3 1.089E+01 1.626E-01 91872.833108 -5.687E+03 636.74
> >   4 9.992E+00 1.349E-01 92811.157892 9.383E+02 640.09
> >   5 1.136E+01 1.892E-01 89994.894507 -2.816E+03 663.40
> >   6 2.454E+01 4.955E-01 34606.221165 -5.539E+04 653.28
>  >  ==================
> >
> >  A longer job (only difference is CUTOFF=70 in that case ) I got
> > something like this
> >  ===================
> >  NFI GEMAX CNORM ETOT DETOT TCPU
> >   1 2.235E+00 9.835E-02 63037.264963 0.000E+00 315.02
> >   2 1.926E+00 8.704E-02 60379.229533 -2.658E+03 297.00
> >   3 2.596E+00 9.187E-02 58256.338687 -2.123E+03 299.82
> >   4 5.105E+00 1.510E-01 56932.353502 -1.324E+03 302.61
> >   5 3.417E+00 1.753E-01 55242.431957 -1.690E+03 305.57
> >   6 3.382E+00 1.303E-01 57670.805897 2.428E+03 308.73
> >   7 3.528E+00 1.431E-01 59077.167956 1.406E+03 311.61
> >   8 5.990E+00 3.978E-01 41851.813249 -1.723E+04 314.97
> >   9 4.477E+00 2.404E-01 54006.746560 1.215E+04 317.90
> >   10 4.752E+00 2.791E-01 52890.347588 -1.116E+03 320.87
> >   11 5.294E+00 3.041E-01 52442.000290 -4.483E+02 321.11
> >  ODIIS| Insufficient progress; reset!
> >   12 2.027E+00 1.090E-01 57184.733418 4.743E+03 294.10
> >   13 2.748E+00 1.956E-01 52859.710375 -4.325E+03 297.20
> >   14 2.175E+00 1.410E-01 54580.632911 1.721E+03 300.05
> >   15 2.765E+00 1.866E-01 53026.895313 -1.554E+03 303.01
> >   16 4.017E+00 2.979E-01 48451.018485 -4.576E+03 306.01
> >   17 3.689E+00 2.535E-01 49096.494350 6.455E+02 309.06
> >   18 5.621E+00 3.912E-01 39573.558492 -9.523E+03 312.16
> >   19 2.160E+00 1.421E-01 52656.205961 1.308E+04 314.94
> >   20 2.746E+00 1.980E-01 50471.977539 -2.184E+03 317.95
> >   21 2.622E+00 1.947E-01 53253.620361 2.782E+03 321.16
> >   22 2.326E+00 1.563E-01 52749.439027 -5.042E+02 321.01
> >   23 3.447E+00 1.939E-01 50260.058884 -2.489E+03 322.45
> >  ODIIS| Insufficient progress; reset!
> >   24 3.125E+00 2.316E-01 52263.955271 2.004E+03 298.20
> >   25 9.174E+00 4.560E-01 28645.700828 -2.362E+04 298.98
> >   26 6.581E+00 3.604E-01 42865.428348 1.422E+04 302.57
> >   27 8.131E+00 4.077E-01 36804.591084 -6.061E+03 304.47
> >   28 8.490E+00 4.228E-01 35472.337851 -1.332E+03 307.96
> >   29 8.293E+00 4.199E-01 37035.599483 1.563E+03 312.21
> >   30 8.650E+00 4.403E-01 31113.206639 -5.922E+03 317.06
> >   31 8.708E+00 4.520E-01 29402.668042 -1.711E+03 335.69
> >   32 8.714E+00 4.610E-01 31226.023423 1.823E+03 334.76
> >   33 8.535E+00 4.664E-01 25902.520906 -5.324E+03 342.20
> >   34 8.569E+00 4.777E-01 24612.360450 -1.290E+03 331.09
> >  ODIIS| Insufficient progress; reset!
> >   35 1.186E+01 3.187E-01 -1117.778641 -2.573E+04 300.17
> >   36 9.641E+00 3.311E-01 -5610.147138 -4.492E+03 303.71
> >   37 2.563E+00 1.361E-01 -12460.838007 -6.851E+03 306.61
> >  ========================
> >
> >  What is wrong in this calculation?
> >  I appreciate your help.
> >
> >  Yong
> >
> > <2.out>_______________________________________________
> > CPMD-list mailing list
> > CPMD-list at cpmd.org
> > http://cpmd.org/mailman/listinfo/cpmd-list
> >
> --
> Pradip K. Biswas, PhD.
> Research Associate, Department of Chemistry;
> Cleveland State University, Ohio-44115
> Phone: 1-216-875-9723
> http://comppsi.csuohio.edu/groups/people/biswas.html
>
>
>
> _______________________________________________
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> http://cpmd.org/mailman/listinfo/cpmd-list
>
>
>


-- 
=======================================================================
Axel Kohlmeyer   akohlmey at cmm.chem.upenn.edu   http://www.cmm.upenn.edu
  Center for Molecular Modeling   --   University of Pennsylvania
Department of Chemistry, 231 S.34th Street, Philadelphia, PA 19104-6323
tel: 1-215-898-1582,  fax: 1-215-573-6233,  office-tel: 1-215-898-5425
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