[Molpro-user] [molpro-user] How to alter the active space

[Tom Keal]

Hi Nevin,

Try adding the keyword "noextra" to the mcscf section. The problem is
that Molpro detects "extra symmetries" above the symmetry you specify
(here none) and does not allow the swapping of two orbitals of different
extra symmetry. If you disable this mechanism with "noextra", the
rotation should then be allowed.

Best wishes,

Tom

PS: It might be a good idea to add a note about this problem in the
manual under the "rotate" command in section 20.5.2. At the moment it's
only mentioned elsewhere (20.6.4).



Nevin Oksuz wrote:
> dear Molpro users and Authors,
> i have the same problem as John L. Payton: i could not swap the orbitals
> 17 and 19 for benzene. i put the input file below.  this input does not
> do any swap! thanks in advance
> ! 2.com --> cas(6,6)/sto-3g guess=(read,alter) for swapping orbitals 17
> and 19
> !
> ***,benzene cas(6,6)/sto-3g alter orbitals 17 and 19
> memory,200,m
> !file,2,2_try.orb
> gprint,basis,orbital,civector
> basis=sto-3g
> geomtyp=xyz
> geometry={
> nosym,noorient
> 12
> Benzene rhf/sto-3g single point for determination of orbitals
> C     0.000000     0.000000     0.000000
> C     0.000000     0.000000     1.400000
> C     1.212436     0.000000     2.100000
> C     2.424871     0.000000     1.400000
> C     2.424871     0.000000     0.000000
> C     1.212436     0.000000    -0.700000
> H    -0.943102     0.000000     1.944500
> H     1.212436     0.000000     3.189000
> H     3.367973     0.000000     1.944500
> H     3.367973     0.000000    -0.544500
> H     1.212436     0.000000    -1.789000
> H    -0.943102     0.000000    -0.544500
> }
> 
> rhf
> put,molden,rot_rhf.molden
> 
> {mcscf
> closed,18   ! this is CAS(6,6)
> occ,24
> state,1
> rotate,17.1,19.1,angle=0
> wf,42,1,0
> cpmcscf,grad,1.1
> }
> put,molden,rot_swap.molden