[molpro-user] MCSCF Convergence and orbital saving.

[Luke Hartley Thomas]

Hi Benj,

Thanks for your suggestion. I have just tried this, and in the process tried fiddling with a few
other things. The commands work (with d, I have not tried e) provided that I do not try to
do the geometry optimisation. However, when I include optg, it defaults back to 0.1e-7 again!

Thanks again,

Luke

On Wed, 20 Jun 2007, Benj FitzPatrick wrote:

> Luke,
> I'm sorry I can't help you with the first part, but for the second I think it
> could be the "e" in your tolerance.  I would try "energy=2.d-7" and see if that
> works.
> Cheers,
> Benj
>
> ---- Original message ----
> >Date: Wed, 20 Jun 2007 12:43:07 +0100 (BST)
> >From: Luke Hartley Thomas <uccalht at ucl.ac.uk>
> >Subject: [molpro-user] MCSCF Convergence and orbital saving.
> >To: molpro-user at molpro.net
> >
> >Dear Molpro users,
> >
> >I am trying to undertake some MCSCF and MRCI calculations with MOLPRO 2006.1
> >patch version 40, but I am having a few problems that I cannot solve with the
> >help of the manual.
> >
> >Firstly,
> >
> >When I perform an MCSCF calculation with the following input, the calculation
> >proceeds normally.
> >
> > memory,100,m
> > file,2,bcl3-min1-mcscf-big.wfu
> > gprint,orbital=5,basis
> > r1=1.758 angstroms
> > r2=1.7581 angstroms
> > r3=1.758 angstroms
> > a1=120.01 degrees
> > a2=120.00 degrees
> > d1=180.0 degrees
> > geometry={
> > B1,
> > Cl1, B1, r1
> > Cl2, B1, r2, cl1, a1
> > Cl3, B1, r3, cl1, a2, cl2, d1
> > }
> > basis={default,sto-3g}
> > {hf
> > wf,54,1,0}
> > basis={default,cc-pvtz}
> > {hf
> > wf,54,1,0}
> > {multi
> > frozen,0,0
> > closed,13,3
> > occ,25,7}
> > optg
> >
> >However, when I try to restart the calculation, and save the orbitals, by using
> the input
> >
> > memory,100,m
> > file,2,bcl3-min1-mcscf-big.wfu
> > gprint,orbital=5,basis
> >
> > geometry={
> > B1,
> > Cl1, B1, r1
> > Cl2, B1, r2, cl1, a1
> > Cl3, B1, r3, cl1, a2, cl2, d1
> > }
> >
> > basis={default,cc-pvtz}
> > {multi
> > save,,5000.3
> > frozen,0,0
> > closed,13,3
> > occ,25,7}
> >
> >the output generates a few new lines of code,
> >
> > Maximum number of shells:             8
> > Maximum number of spin couplings:   429
> >
> >And then the following error message:
> >
> >       Storage for configuration lists 5182008, coupling coefficients3670869,
> >       address lists*******
> >
> >       Molecular orbitals read from record     2140.2  Type=MCSCF/MULTI (state 1.1)
> >
> >       Wavefunction dump at record             2140.2
> >
> >       Convergence thresholds  0.10E-01 (gradient)  0.11E-05 (energy)  0.10E-02
> >       (step length)
> >       insufficient memory available - require              162579456  have
> >              15685319
> >       the request was for real words
> >
> >       GA ERROR fehler on processor   0
> >
> >It appears to be that MOLPRO is trying to do some type of spin orbit
> >calculation(?), which seems to be a lot slower, and requires a lot more memory
> >than I have available. Can anybody indicate why just saving the orbitals
> >should cause molpro to behave in this way, and can I do anything to prevent it?
> >I wish to use the orbitals as the reference for a CI calculation.
> >I notice that MOLPRO 2002.3 did not behave in this way - the save command just
> >caused the same calculation as before to be performed.
> >
> >Secondly,
> >
> >I would like to change the convergence criterion on the MCSCF energy
> calculation during
> >my geometry optimisation. Again, I have consulted the manual, but I do not seem
> to have
> >any success with the commands given.
> >
> >My input is as follows:
> >
> > memory,100,m
> > file,2,bcl3-ts5-mcscf-big.wfu
> > gprint,orbital=5,basis
> >
> >
> > geometry={
> > B1,
> > Cl1, B1, r1
> > Cl2, B1, r2, cl1, a1
> > Cl3, B1, r3, cl1, a2, cl2, 180.0
> > }
> >
> > basis={default,cc-pvtz}
> > {multi,
> > frozen,0,0
> > closed,13,3
> > occ,25,7
> > thresh,energy=0.2e-6}
> > put,molden,bcl3-ts5-mcscf-big-sp.mld
> > {optg
> > root,2
> > method,qsd
> > hessian,read}
> >
> >The manual also suggests I can use the command "energy" after the multi command
> to change the convergence
> >threshold. I have tried:
> >
> >multi,energy=0.2e-6
> >
> >and
> >
> >multi
> >energy=0.2e-6
> >
> >neither of these seem to work. Either the calculation complains about the
> syntax, or just carries on with the
> >normal criterion, 0.1e-7.
> >
> >I have also tried:
> >
> >accuracy,energy=0.2e-6
> >
> >in the MULTI command block.
> >
> >This is also ignored. Is this problem something to do with the optg command
> altering the convergence thresholds
> >after I have changed them? I believe that the convergence criterion is tighter
> when performing an optimisation of
> >the geometry. Can anybody suggest the correct syntax to use.
> >
> >Many thanks in advance for your help, (and sorry for the length of the enquiry!)
> >
> >Luke Thomas
> >Department of Chemistry
> >University College London
> >
> >
>