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Subsections
6.18 MCLR — A Program for Linear Response Calculations
MCLR computes response calculations on single and multiconfigurational
SCF wave functions. One of the basic uses of MCKINLEY and MCLR
is to compute analytical hessians (vibrational frequencies, IR intensities, etc).
MCLR can also calculate the Lagrangian multipliers for
a MCSCF state included in a state average optimization and construct the effective
densities required for analytical gradients of such a state.
The use of keyword RLXRoot in the RASSCF program is required.
In both cases the explicit request of executing the MCLR module is not
required and will be automatic.
We postpone further
discussion about MCLR to section 6.15.
It follows an example of how to optimize an excited state from a previous
StateAverage (SA) CASSCF calculation.
&GATEWAY
Title= acrolein minimum optimization in excited state 2
Coord=$MOLCAS/Coord/Acrolein.xyz
*$
Basis= sto3g
Group=NoSym
>>> Do while
&SEWARD
&RASSCF
Title= acrolein
Spin= 1; nActEl= 6 0 0; Inactive= 12; Ras2= 5
CiRoot= 3 3 1
Rlxroot= 2
&SLAPAF
>>> EndDo
The root selected for optimization has been selected here with the keyword
Rlxroot in RASSCF, but it is also possible to select it
with keyword SALA in MCLR.
Now if follows an example as how to compute the analytical hessian for the lowest
state of each symmetry in a CASSCF calculation (SCF, DFT, and RASSCF analytical
hessians are also available).
&GATEWAY
Title=pbenzoquinone anion. Casscf optimized geometry.
Coord = $MOLCAS/Coord/benzoquinone.xyz
Basis= sto3g
Group= X Y Z
&SEWARD
&RASSCF
TITLE=pbenzoquinone anion. 2B3u state.
SYMMETRY=2; SPIN=2; NACTEL=9 0 0
INACTIVE=8 0 5 0 7 0 4 0
RAS2 =0 3 0 1 0 3 0 1
&MCKINLEY; Perturbation=Hessian
The MCLR is automatically called after MCKINLEY
and it is not needed in the input.
Keyword  Meaning

SALA  Root to relax in geometry optimizations

ITER  Number of iterations



Next: 6.19 GENANO A
Up: 6. Program Based Tutorials
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