[Columbus] Atomic Overlap Integrals

[Thomas Mueller]

On Wed, 24 Apr 2013, Zhen Lu wrote:

> Hello everyone,
> when I print the atomic orbital overlaps with iwfmt.x I get diagonal elements that are not 1. Most of them are 1, but some of them are 4. I have noticed
> that this is for d2+ orbitals only. What are the ramifications of this?
> I am trying to take the inner product between two sets of molecular orbitals by expanding in terms of the atomic coefficients and their overlaps using the
> mocoef files and the aoints file. I am not getting inner products of 1 between the same sets of molecular orbitals and I am looking for the cause. Am I
> correct in that this should give me the proper MO overlaps?
>
> Thanks as always,
> Zhen
>
>

   The normalization of the AO basis to unity is merely
   a matter of convention. Any other value is equally admissable
   since only the molecular orbitals are required to be orthonormal.
   In case of dalton, the AO basis (in SAO as well as as in CAO
   basis) is *not* normalized to unity.

   C(t)*S(ao)*C = 1 = S(mo)

   holds, provided you use the MO coefficients from
   the mocoef files and the overlap integrals from the aoints
   file.

Regards,

  thomas

-----------------------------------------------------------
Dr. Thomas Mueller
Institute for Advanced Simulation (IAS)
Juelich Supercomputing Centre (JSC)

Phone:  +49-2461-61-3175
Fax:    +49-2461-61-6656
E-mail: th.mueller at fz-juelich.de
WWW:    http://www.fz-juelich.de/jsc/

JSC is the coordinator of the
John von Neumann Institute for Computing (NIC)
and member of the
Gauss Centre for Supercomputing (GCS)
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