canorb energies in mcscf

[Falcetta_Michael]

Dear Molpro Users:

I am doing an mcscf, extracting several states of a cation system
(equally weighted) and trying to understand the canonical orbital
energies I am getting.  In the symmetry block under consideration, there
are 2 core and 7 valence orbitals and thus the first 9 orbitals in the
symmetry block are accounted for.  If I include only 9 orbitals in the
active space for this symmetry block, and print the canorbs the energy
of the 10th (i.e. first nonactive orbital) is about -.07 au and the
energy of the 9th orbital is positive.  I then start with these
canonical orbitals and allow 11 orbitals in the active space for this
the symmetry block and now the 12th orbital has an energy of about -.07
and the energies of the 10th and 11th orbitals are positive.  Finally I
have expanded the active space to include 15 orbitals in this symmetry
and the Occ numbers and energies are given below.  I have also tried to
rotate orbitals 14 and 16 to ensure that the initial guess includes the
orbital I want in the active space.  You'll note that the energies of
some of my active orbitals are above 1 hartree.  My question is: are
these energies correct? and if so, does that mean that I am getting very
high energy orbitals into the active space?  Then how do I get the
calculation use the much lower energy external orbitals (for example
orbs 16 and 17 below)?

Thanks in advance for your help

Mike Falcetta


Orb     Occ        Energy  

   1.1  2.00000   -21.113878  

   2.1  2.00000   -11.741709  

   3.1  1.97590    -1.896946   

   4.1  1.72258    -1.102576   

   5.1  1.91319    -0.973930   

   6.1  1.53756    -0.906814   

   7.1  1.33268    -0.737594   

   8.1  0.49390    -0.265931   

   9.1  0.01706     0.401921   

  10.1  0.02853     0.743152   

  11.1  0.01646     0.899204   

  12.1  0.00779     1.153367   

  13.1  0.00348     1.252850   

  14.1  0.00298     1.606205   

  15.1  0.00194     1.685566   
 
 16.1  0.00000    -0.071171

  17.1  0.00000    -0.070372

  18.1  0.00000    -0.061979

  19.1  0.00000    -0.040635

  20.1  0.00000    -0.039509

  21.1  0.00000    -0.036030

  22.1  0.00000    -0.025585

  23.1  0.00000    -0.017070
Dr. Mike Falcetta

Associate Professor of Chemistry
Roberts Wesleyan College
2301 Westside Drive
Rochester, NY 14624