Dear all,

I am currently working on a conical intersection search using Gaussian16 on Linux, and I've encountered an error that I'm having difficulty resolving. I would greatly appreciate any insights or suggestions you may have.

Here is my route section:

#p Opt=(Conical,maxcycle=400) CASSCF(6,6,nroot=2)/6-31g SCF (maxcycle=6000,conver=6,vshift=300) nosymm

The calculation appears to stop running, and the error message in the 9th last lines of the log file reads as follows:

FoFCou: FMM=F IPFlag=0 FMFlag=100000 FMFlg1=0

NFxFlg=0 DoJE=T BraDBF=F KetDBF=T FulRan=T

wScrn=0.000000 ICntrl=500 IOpCl=0 I1Cent=200000004 NGrid=0

NMat0=1 NMatS0=1 NMatT0=0 NMatD0=1 NMtDS0=0 NMtDT0=0

Symmetry not used in FoFCou.

Harris En= -958.757063311024

JPrj=0 DoOrth=F DoCkMO=F.

Leave Link 401 at Thu Nov 30 10:48:02 2023, MaxMem=5368709120 cpu:78.3 elap:78.6

(Enter /gpfs/softs/softwares/Gaussian/g16/l405.exe)

The intersection I'm looking for is between the ground and first excited states, so I'm putting the weight of the states after my molecule specification section as:

0.5 0.5

I'm uncertain whether this qualifies as an error, but the calculation halts at the initial step of the process. Any guidance on resolving this issue would be immensely helpful.

Thank you for your time and assistance.