[molpro-user] Atom in an electric field: why the error message?

[Kirk Peterson]

Phillip,

I think for the atom you need to turn symmetry off, since the dipole  
field in the z-direction will break symmetry.  In your molecular case,  
presumably
you only tried a field in the z-direction, which would not break your  
linear molecule symmetry.

regards,

Kirk

On Mar 16, 2009, at 2:10 PM, Phillip Price wrote:

> I am a new Molpro user.
>
> It doesn't get much simpler than this: I'm trying to calculate atomic
> and molecular polarizabilities, by looking at either energies or
> dipoles as a function of field.  Oddly (to me) things seem to work
> fine with molecules that I have tried, but not with atoms. For
> example, hydrogen atom in an electric field:
>
> geometry={H;}
> hf
>
> This works fine.
>
> But:
>
> geometry={H;}
> dip,0.0,0.0,0.001
> hf
>
> This generates an error:
> ?ERROR: FINITE FIELD PERTURBATION OPERATOR DMZ NOT TOTALLY SYMMETRIC
>
>
> I have also tried Li and O, with the same error.
>
> If I try this with a hydrogen _molecule_ instead of a hydrogen _atom_,
> there's no problem: Molpro runs without error and generates sensible
> answers.
>
> This makes me think that with an atom, Molpro expects spherical
> symmetry and generates an error when it doesn't find it, but with a
> molecule it doesn't expect symmetry anyway so there is no problem.
> But I don't actually know that that is the issue.  And more to the
> point, I have tried specifying symmetry (using SET,SYMMETRY=Z for
> example) with no success.
>
> Can someone point me the right direction?  I would appreciate it.
>
> By the way, I am running Molpro 2006.1, because that is what is
> available on my lab's mainframe. I can switch to a more recent version
> if I have to, if that is the problem.
>
> Thanks in advance for any help.
>
> Phil Price
> Lawrence Berkeley National Laboratory
>
>
>
>
>
>
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