# OPTIM + ORCA: double-ended connection (NEWCONNECT), N6 chain -> 3 N2

DNEB between the two minima, BFGSTS on each candidate, path down both sides, repeat until connected (Dijkstra).
Start = chain (POINTS), finish = 3 N2 (`finish`, coordinates only). Run: `sbatch job.sh` (days; no restart file).
Output: `OPTIM.out`, `path.info` (every min-TS-min found), and the connected path if one is found.
This example shows the input for a connection run; it is slow and has not been run to the end. The 3 N2 end
is a loose complex, and PERMDIST may pair its atoms with the chain's in a way that makes the connection harder.

ORCA and MPI: job.sh swaps the Open MPI 5.0.5 of module orca/6.1.1 for 4.1.7 (5.0.5 now and then segfaults inside
ORCA; the "reloaded with a version change" message in slurm-*.out is expected) and turns core binding off.
The ORCA line of odata runs `./orca_retry.sh`, which runs ORCA and reruns a failed call (up to 3 times); failures are
logged in `orca_failures/failures.log`, and job.sh prints a NOTE if that file exists. A hung call is not caught.