Try to increase TIMLIM (I'm afraid the default value is too small, 600 min) and restart geometry optimization with the last-step coordinates.
On Fri Sep 7 '12 3:25pm, Danas wrote
>I am trying to optimize and find the vibrational nodes of a molecule.
>While for some molecules it was possible to solve this, for other I got the error "FAILURE TO LOCATE STATIONARY POINT", and eventually it didn't calculate the vibrational nodes.
>Even so, the log file ended with "
> EXECUTION OF FIREFLY TERMINATED NORMALLY".
>I also noted that for molecules similar with this one, it took several days to optimize and calculate the vibrational nodes (Pentium Core 2 Duo 2.6GHz). I don't know, yet, how should I speed up the process.
>Are NCONV and OPTTOL to tight for calculating the vibrational nodes?
>This is the input file:
>! Input file for FireFly
> $CONTRL SCFTYP=RHF RUNTYP=OPTIMIZE MAXIT=500 MULT=1 COORD=UNIQUE ICHARG=1 $END
> $CONTROL INTTYP=HONDO ICUT=11 ITOL=30 $END
> $CONTRL DFTTYP=B3LYP $END
> ! $CONTRL EXETYP=CHECK $END
> $SYSTEM MEMORY=20000000 $END
> $BASIS GBASIS=N31 NGAUSS=6 $END
> $BASIS NPFUNC=1 NDFUNC=1 $END
> $BASIS DIFFSP=.FALSE. $END
> $SCF DIRSCF=.TRUE. FDIFF=.FALSE. NCONV=6 $END
> $STATPT OPTTOL=1e-5 NSTEP=500 HSSEND=.TRUE. $END
> $FORCE VIBANL=.TRUE. $END
>Please give me a hint how to modify the input file in order to avoid the failure concerning the stationary point and speed up the process of computing.
>I attached the log file.
>With best regards,