Download MOLPRO

3
25
INTRODUCTORY EXAMPLES
***,OH
geometry={O;H,O,1.83}
set,symmetry=[2,3,1],spin=1
! 2Pix, 2Piy, and 2Sigma+ states (specifying spin=1 is optional)
runcas
! SA-CASSCF for all three states
examples/
set,symmetry=[2,1]
! remove Piy
oh_runmrci2.com
runmrci
! MRCI for 2Pix and 2Sigma+
This produces
RESULTS
METHOD
CASSCF
CASSCF
CASSCF
MRCI
MRCI+D
MRCI+P
MRCI
MRCI+D
MRCI+P
STATE
1.2
1.3
1.1
1.2
1.2
1.2
1.1
1.1
1.1
S
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
0.5
ENERGY
-75.41331789
-75.41331789
-75.24125256
-75.55518444
-75.56014871
-75.55853208
-75.39442202
-75.40040680
-75.39846312
DIPX
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
DIPY
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
0.0
DIPZ
0.67158730
0.67158730
0.69975340
0.66457191
0.66457191
0.66457191
0.70484623
0.70484623
0.70484623
You may want to extend the active space to include the 2π orbitals. This can be achieved by
setting the variable OCC.
***,OH
geometry={O;H,O,1.83}
!
set,symmetry=[2,3,1],spin=1
occ=[4,2,2]
!
runcas
!
set,symmetry=[2,1]
runmrci
!
Geometry definition
! 2Pix, 2Piy, and 2Sigma+ states
4 sigma and 2 pi occupied
SA-CASSCF for all three states
! remove Piy
MRCI for 2Pix and 2Sigma+
examples/
oh_runmrci3.com
For accurate calculations of the electronic transition moment, also the 1δ orbitals contribute
significantly. These are in symmetry 1 (δx2 −y2 ) and 4 (δxy ). In order to force the 5a1 orbital to
become the δ, we must use the SYM directive in the SCF calculation. Since it is not possible to
insert this into the procedure, we must write the SCF input explicitly.
***,OH
basis=avqz
!
geometry={O;H,O,1.83}
!
set,symmetry=[2,3,1],spin=1
occ=[5,2,2,1]
!
hf
!
sym,1, 1,1,1,1,2
!
runcas
!
set,symmetry=[2,1]
runmrci
!
Use aug-cc-pVQZ basis
Geometry definition
! 2Pix, 2Piy, and 2Sigma+ states
4 sigma, 2 pi, 1 delta occupied
do scf calculation
examples/
5th orbital in symmetry 1 has extra symmetry 2 (= oh_runmrci4.com
delta)
SA-CASSCF for all three states
! remove Piy
MRCI for 2Pix and 2Sigma+
Note that this calculation is quite expensive!
3.8.3
MP2 geometry optimization
The following input performs an MP2 geometry optimization for water.