FCI frequencies

[Peter Knowles]

This one's simple to explain. The program cannot deal with a change in
symmetry between one geometry and the next, and this is certainly what
happens when the frequencies are done numerically. The solution is to
run the whole calculation with symmetry switched off.
Peter

At Wed, 21 Nov 2001 11:16:25 +0100,
Luis  wrote:
> 
> Dear all,
> I am doinf a FCI calculation on the H3 system in an alpha dec osf4.0
> workstation.
> The optimization runs OK, but the frequency calculation
> crashes at the first FCI step:
> ---------------------------------------------------------------------------------
>  Run Hamiltonian processor DAVIDSON
>  Symmetry:                   5
>  Trial vector:                  0.00
>  Result vector:                 0.00
>  Maximum iterations:           35
>  Convergence threshold:         0.0000100
>  RHS vector:                    0.00
>  Hamiltonian shift:             0.0000000
>  Output threshold:              0.0500000
>  Options:                        0
>  Number of roots:             1
> 0Hamiltonian diagonaliser entered at time   5546.38
> 
>  ERROR EXIT
> --------------------------------------------------------------------------------
> 
> Does anyone have a suggestion?
> The input file is:
> 
> ***,h3lin_fci
> memory,100,M
> file,1,h3lin_fci.ints
> file,2,h3lin_fci.wfu
> basis=AVTZ
> geometry={;
> angstrom
> H1;H2,H1,r;H3,H2,r,H1,180.,
> }
> r=0.8
> 
> int
> thr,40,40
> pri,0
> 
> hf
> wf,3,5,1
> accu,15
> orbprint,2
> pop
> fci
> wf,3,5,1
> optg,gaussian
> frequencies
> 
> 
> Luis Rodriguez
> 
> 
> _____________________________________________
> 
> Luis Rodriguez Santiago
> Unitat de Quimica Fisica
> Departament de Quimica
> Edifici C
> Universitat Autonoma de Barcelona
> 08193 Bellaterra, Spain
> 
> Phone: +34 93 5812173
> Fax: +34 93 5812920
> E-mail: luis at klingon.uab.es
> _____________________________________________
> 
> 
> _____________________________________________________
> 
> Luis Rodriguez Santiago
> Laboratoire Analyse et Environnement, CNRS UMR 8587
> Université d'Evry-Val d'Essonne
> Boulevard François Mitterrand 91025 Evry Cedex
> 
> Tel: 33 1 69 47 76 45
> Fax: 33 1 69 47 76 55
> E-mail: Luis.Rodriguez at chimie.univ-evry.fr
> _____________________________________________________
> 

-- 
Prof. Peter J. Knowles              
Email P.J.Knowles at bham.ac.uk  Phone +44-121-414-7472  Fax +44-121-414-7471
School of Chemical Sciences, University of Birmingham, Birmingham, B15 2TT, UK
WWW http://www.tc.bham.ac.uk/~peterk/