there is no direct control over the energy gap for penalty-based CoIn
optimization procedures. The gap can be controlled indirectly using
parameters defining a penalty function. The larger is the "strength"
of penalty function the smaller will be the gap. With Firefly, the
strength is controlled by the parameter B of $mcaver group.
On Sat Oct 22 '16 11:50am, GrEv wrote
>I am doing optimization of the minimum energy conical intersection using the penalty function method, with the following input (from the manual, p. 176) :
>$MCAVER TARGET=MIXED PENLTY=2 XGRAD=.F. $END
>$STATPT OPTTOL=0.00005 NSTEP=500 method=qa trmax=0.05 dxmax=0.05
> HSSEND=.f. $END
>$NUMGRD ORDER=2 DELTA=0.01 ISTATE=1 JSTATE=2 NGRADS=2 PRAXES=1 $END
>Using this input I found a conical intersection (CoIn), with the final gap between the states of 0.003. I'd like however to have a smaller gap, let's say 0.0001. How this could be done. I've tried to use the SHIFT option in $MCAVER, setting SHIFT=0.0001. It however didn't do the job. I got a CoIn with almost the same gap as before.