[molpro-user] 2e Integrals

[Peter Knowles]

Try the following:

geometry={nosym;he} ! or whatever you like
int;spri,2

Note that the integrals are multiplied by a factor of 0.5 for each of 
the 3 possible permuational symmetry elements: (ij|kl) i.eq.j or k.eq.l 
or ij.eq.kl, so the integrals that are printed need multiplying by 1, 2 
4 or 8 as appropriate.

The format of the integrals with symmetry is a little more complicated, 
but maybe you can figure it out through appropriate comparison.

If you don't like the print format, and have source code, then you 
should go to src/sort/aosortv.f, subroutine printints.

Peter Knowles

Ben Robinson wrote:
> Hello,
> 
> My name is Ben Robinson and I work in the theoretical chemical physics group
> of Shaul Mukamel here at the University of California at Irvine.  I recently
> acquired an evaluation copy of MOLPRO and have a technical question
> pertaining to my specific requirements.
> 
> I need to obtain the 2 electron integrals of the Coulomb type for further
> calculations by my program.  I know how to save file 1 and file 2 but these
> files are readable only by MOLPRO.  I also noticed many print options for 1
> electron quantities but not for 2 electron quantities.
> 
> How can I print/load/use the 2 electron integrals for a molecule?  I need
> them in the atomic orbital basis set.  This will only be an N squared
> matrix.
> 
> Thank you for your assistance,
> 
> Ben Robinson
> UCI
>