Posted by Marco Marazzi on February 01, 2010 at 19:13:53:
Dear Molcas users,
I have problems in the calculation of the Lagrangian multipliers (&MCLR) that I need for a CASSCF minimum energy path with analytical gradients.
The message shown is:
"No convergence for perturbation no: 1. Increase Iter."
Even increasing the number of iterations to 1000, the system does not converge.
My input is the following:
>>> Do while
&SEWARD
>>> If ( Iter = 1 ) <<<
&SCF
Charge
1
UHF
>>> EndIf <<<
&RASSCF
SPIN
1
CHARGE
1
NACTEL
6 0 0
FROZEN
0
INACTIVE
23
RAS2
6
CIROOT
2 2
1 2
1 1
RLXRoot
2
&MCLR
SALA
2
Iterations
1000
&ALASKA
&SLAPAF
Constraints
a = Sphere
Value
a = 0.1
End of Constraints
MEP-search
NMEP
200
>>> EndDo
With numerical calculation of the gradients (no &MCLR required) no problems are found, but it needs much more time.
Are there other ways to calculate CASSCF analytical gradients?
Thanks in advance