Old versions allowed you to do this by loading the orbitals into a matrix using the
MATROP facility (among the last sections of the online user manual), but it appears
that the new versions allow you to do this directly in the MULTI program. The command
is ROTATE, and I believe the syntax is
ROTATE,orb.sym,orb.sym,angle
where orb.sym=i.j is the ith orbital in the jth symmetry group. I always work in C1
symmetry to prevent spurious symmetric results, so isym is always one for me. Angle
is the angle (in degrees, I think) of rotation between the orbitals. If angle=0, then
the program assumes that the orbitals are to be interchanged (i.e., it assumes
angle=90). For example, for a molecule with 98 electrons in a singlet closed-shell
reference, if I wanted to interchange orbitals 48 and 46 of the reference, the command
would
be (again, in C1 symmetry):
rotate,48.1,46.1,0
For more information, check the users manual under the MULTI section, or look in the
index.
Hope this helps.
Seth Olsen
Biophysics & Computational Biology
University of Illinois
Matthew E. Cremeens wrote:
> Hello,
>
> Please pardon my ignorance. I am trying to select orbitals for a
> CASSCF(8,8)/6-31G(d) calculation. I have not been successful at reordering
> the orbitals so that I have the appropriate orbitals in the active
> space. What is the required input for such a task? Below is a copy of my
> input.
>
> Thank you! Matt
>
> *** Cyclopropylidene- CASSCF(8,8) TS for ring opening
> !geom from CASSCF(8,8)/6-31G*
> gprint,basis
> gprint,orbitals
> gprint,orbitals=24 !C7H6(7*6+6*1=48e-'s)
>
> geomtyp=xyz
> geometry
> 13
> cyclopropylidene CAS (8,8) TS for ring opening
> C 1.342641 0.258753 0.047381
> C 1.817933 -0.755535 0.952996
> C 1.130405 -1.521801 -0.046884
> C -0.342529 -1.578292 -0.255862
> C -0.986052 -0.403695 -0.304852
> C -0.043030 0.710103 -0.268184
> C -0.336282 2.002118 -0.501311
> H 2.125952 0.918420 -0.295194
> H 1.713279 -2.308094 -0.504455
> H -0.810640 -2.544188 -0.293146
> H -2.049728 -0.274263 -0.365651
> H -1.345401 2.313608 -0.701213
> H 0.418561 2.766816 -0.489174
> end
>
> memory,96,m
> cartesian
> basis=6-31G(d)
> hf
> orbital,2100.2
> casscf
> core,7
> closed,20
> occ,28
> start,2100.2,
> GUESS={read,orb,20.1,AS,21.1,FROM,2100.2;read,orb,29.1,AS,28.1,FROM,2100.2}
> wf,48,1,0
> orbital,2101.2
>
