[CPMD-list] PROGRAM STOPS IN SUBROUTINE UINV| ILLEGA

[Juerg Hutter]

Hi

your problem seems to be that the wavefunction optimization
didn't converge. If this happens with PCG MINIMIZE
you can see that the step size goes to zero (LAMBDA=10^-309
in your case).
Experience tells us that this usually happens with systems
that a far from equilibrium (e.g. at the beginning of a
geometry optimization). It is therefore a good
practise to start an optimisation with a relaxed
convergence criteria and tighten it when approaching
the minimum.
There is an automatic scheme to do this with the LBFGS
optimizer, have a look in the manual.

In general, I would advice everybody to treat optimizations
not as black box jobs. Have a look at the output and
stop runs when irregularities appear. Then restart
with an adapted set of options.
This way a lot of computer time can be saved.

regards

Juerg Hutter

----------------------------------------------------------
Juerg Hutter                   Phone : ++41 1 635 4491
Physical Chemistry Institute   FAX   : ++41 1 635 6838
University of Zurich           E-mail: hutter at pci.unizh.ch
Winterthurerstrasse 190
CH-8057 Zurich, Switzerland
----------------------------------------------------------


On Sun, 27 Apr 2003 cdy2000 at vip.sina.com wrote:

> Hello, every CPMDer!
>
>     when I optimize the GEOMETRY of a oxide, there is the problem after many steps:
>
> 3485  3.416E-04   2.018E-05   -1447.214130    0.000E+00    185.50
>  LINE SEARCH: WARNING! 2*E0-4*E1+2*E2 == 0.0
>  LINE SEARCH : LAMBDA=.399-309       ENERGY =          -1447.2141
> 3486  3.416E-04   2.018E-05   -1447.214130    0.000E+00    185.38
>  LINE SEARCH : LAMBDA=.797-308       ENERGY =          -1447.2141
> 3487  3.416E-04   2.018E-05   -1447.214130    0.000E+00    185.56
>  LINE SEARCH: WARNING! 2*E0-4*E1+2*E2 == 0.0
>  LINE SEARCH : LAMBDA=.747-310       ENERGY =          -1447.2141
> 3488  3.416E-04   2.018E-05   -1447.214130    2.274E-13    185.81
>  LINE SEARCH : LAMBDA=.747-309       ENERGY =          -1447.2141
> 3489  3.416E-04   2.018E-05   -1447.214130    0.000E+00    186.19
>  UNIV| THE LEADING MINOR OF ORDER    1 IS NOT POSITIVE DEFINITE,
>  UNIV| AND THE FACTORIZATION COULD NOT BE COMPLETED.
>
>
>  PROGRAM STOPS IN SUBROUTINE UINV| ILLEGAL RESULTS DPOTRF
>
> then the process ends, I want to know how to solve the problem in modifying the parameters of the input code?
>
>     Thanks for any help!
>
> Sincerely Cao Dayong
> ______________________________________
>
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