Apolgy. Print out of MOs from two different sets:

 The "utter nonsense" part of this letter was not meant to be offensive
 in any
 way to you!!!  It was meant to be offensive to ME since the original question
 was misleading, erroneous and down-right poorly thought out and stated!
 Thank you again to those people who have given me suggestions and to those that
 are reading these email messages.
 Iraj.
 > Iraj Daizadeh wrote:
 >
 > > Hello.
 > >
 > > The overall project was to simply construct an overlap matrix of MO's
 > > from
 > > different sets.  I have summarized replies to the previous message I
 > > submitted
 > > (utter nonsense!).
 > >
 > > The problem was to save the MO's from an initial run of Gaussian.
 > > Then during
 > > a second run read these in and project onto them atomic overlaps and
 > > the MOs of
 > > the current calculation.  Lets take a closer look at the problem:
 > >
 > >         Example:
 > >
 > >          trivial model system H-H+
 > > run 1
 > > H -- H+     -- > coefficients of expansion of MO's print out from
 G94
 > >
 > > run2
 > > H+--H       -- > read in MO's from checkpoint file and construct:
 > >
 > >                 (Smo)ij  = sum_{mu,nu}  Cmu,i  * (Sao)mu,nu  * Cnu,j
 > >
 > > Now to do this I did the following:
 > >
 > >                 First I printed out the coefficients of Mo's from the
 > > first run
 > > by introducing a link into G94 called l612.F.  The line is shown
 > > below:
 > >
 > >       Call FileIO (2,-IRwCa,NBSq,V,0)
 > >       do 200 i=1,NBsq
 > > 200     write (IUnitA,2010) V(i)
 > >
 > > 2010    format (E40.30)
 > >
 > >                 Also I print out Overlap matrix over atomic orbitals:
 > >
 > >       NTT = Nbasis*(NBasis+1)/2
 > >       Call FileIO(2,-IRwSao,NTT,V,0)
 > >       do 211 i=1,NTT
 > > 211     write (IOvlp,2010) V(i)
 > >
 > > Now I rerun G94 and print out the IRwCa again for the new molecule.
 > >
 > > (BE WARNED: Fortran is the transpose of C/C++; that is: F(i,j) =
 > > C[j][i];)
 > >
 > > In my C code I construct the overlap matrix myself.  This is a very
 > > cumbersome
 > > method for doing this but it works!!!  Now for the C_{pho,k}'s from
 > > the same
 > > calculation, of course, the Smo Matrix should be unitary.  But for
 > > different
 > > combinations of MO set this is not the case *yet some symmetry should
 > > be there
 > > ** it depends on your system of course ** *.
 > >
 > > This is my no means the best possible methodology I would appreciate
 > > any other
 > > solutions.  Any comments, questions, or suggestions would be
 > > appreciated.
 > >
 > > Iraj.
 > >
 > > Hi Iraj,
 > >
 > > Use the option IOP(3/33=1).
 > >
 > > ***************************
 > > *******************************************
 > > *    Lorsque la chance s'envole,
 > > *
 > > *               Lorsque la raison decole,
 > > *
 > > *                          Il nous reste la picole.
 > > *
 > > *
 > > *********************************************************************
 > >
 > >                                                        Ahmed
 > > Bouferguene
 > >
 > > ---
 > > Hi Iraj,
 > >
 > > Yes the matrix you get is the matrix S_{\mu , \nu} which is the
 > > overlap
 > > between atomic orbitals. Now, the overlap between molecular orbitals,
 > > if
 > > my memory is still good should be zero since this is one of the
 > > constraint in the derivation of the Hartree-Fock equation.
 > >
 > >                                                        Ahmed
 > > Bouferguene
 > >
 > > --
 > >
 > >    Add IOP(3/33=1) to get all of the one electron operator matrices in
 > >
 > > the log file.
 > >
 > > Doug Fox
 > > --
 > > Hi Iraj,
 > >
 > > as far as I know there is no such option. However, the overlap
 > > between different sets of orbitals during an SCF calculation is
 > > evaluated if you set iop(5/14=1) and scf=dm which will activate
 > > the conventional (and very slow) direct minimization technique
 > > proposed by Seeger and Pople (J. Chem. Phys., 65 (1976), 265-271)
 > > in L503.
 > >
 > > You may want to cut out the responsible part of the code (mainly
 > > subroutine BESSRT) and wrap your own code (reading of MO input,
 > > overlap matrix etc.) around it.
 > >
 > > I would very much appreciate if you could post a summary if you
 > > get more replies on this topic.
 > >
 > > Stephan Irle
 > > --
 > >
 > > G9x does exactly this automatically (default,) I believe.
 > >
 > > John
 > >
 > >    If the intention is to use this as an initial guess it is done by
 > > default.
 > >
 > > Doug Fox
 > > --
 > >
 > >   Iraj,
 > >
 > >    If the point is to get this into the checkpoint file you can use,
 > >
 > > %chk=mychk
 > > #  ...  Guess=(Read,Save,Only)
 > >
 > > which will pick up the previous MO's, project onto the new basis set,
 > > save them to the checkpoint file and then only do properties before
 > > quiting.  Then you could pick them up from the checkpoint file for
 > > visualizing
 > > etc.
 > > --
 > >
 > > --
 > > Iraj Daizadeh
 > > Department of Chemistry
 > > University of California
 > > One Shields Ave.
 > > Davis, CA  95616-5295
 > > Phone:  916.754.8695
 > > Fax:    916.752.8995
 > > email:  daizadeh;at;indigo.ucdavis.edu
 >
 >
 >-- End of excerpt from Stephan Irle
 --
 Iraj Daizadeh
 Department of Chemistry
 University of California
 One Shields Ave.
 Davis, CA  95616-5295
 Phone:  916.754.8695
 Fax:    916.752.8995
 email:  daizadeh;at;indigo.ucdavis.edu