[molpro-user] MCSCF Convergence and orbital saving.

[Benj FitzPatrick]

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
>
>