ROVGF and UOVGF Keywords
Last Update: 12/31/2000

These method keywords request an Outer Valence Green's Function (propagator) calculation of correlated electron affinities and ionization potentials [137,138,139,140,141,329,142,143]. Either R or U must be specified with OVGF. The unrestricted code requires a two-electron integral file as well as &ltia||bc> transformed integrals. ROVGF calculations default to storage of <ia||bc> integrals, but can be run Tran=Full to save CPU time at the expense of disk usage, or with Tran=IJAB to save on disk space at the expense of CPU time. In the latter case, electron affinities are not computed.

Use Iop(9/11=100) to specify the starting and ending orbitals to refine as input (in a separate input section with a terminal blank line). By default, all orbitals are used.

These keywords require the starting and ending orbitals to refine as input (in a separate section with a terminal blank line).

FC
This indicates “frozen-core,” and it implies that inner-shells are excluded from the correlation calculation. This is the default calculation mode. Full specifies the inclusion of all electrons, and RW and Window allow you to input specific information about which orbitals to retain in the post-SCF calculation (see the discussion of the MPn keywords for an example).

Single point energy calculations only.

For ROVGF calculations, the results for each orbital appear as follows:

 Method   Orbital  HF-eigenvalue 3rd-order Polestrength
   A:        6     19.59832      17.47750      .86138
   B:        6     19.59832      17.51817      .86527
   C:        6     19.59832      17.56548      .86406
 Renormalization of interaction, recommended value
 Orbital  HF-eigenvalue 3rd-order Polestrength
    6     19.59832      17.47750  .86138

The first part of the output gives the results from the three OVGF methods [139]. The third-order column in the final line gives the estimate of ionization potential/electron affinity (which property is given depends on whether the orbital is occupied or not, respectively) for the specified orbital. The pole strength is a measure of how easy it is to make this excitation, with 1.0 as the maximum value. Note that orbitals are listed in the output in order of symmetry (and not necessarily in numerical order).

For UOVGF calculations, the equivalent results appear in the output like this:

 Summary of results for alpha spin-orbital   6:
 ...
 Outer Valence Approximation:  .64377D+00 au    17.518 eV

These results are the same as for method B from the ROVGF calculation.

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