Dear Alexandra,
Yes, you can do PES of uni, bi, tri,
'all-that-your-cpu-can-hold-as-long-as-it-doesn't-bust' dimensions ;)
Just be careful with the parameters you use to make the relaxed PES.
Peter mencioned also the use of the opt=loose for when some optimizations get
stuck. It's a way of working, although I use a different approach. I reoptimize
points that don't converge in a solo calculation, with the same converge
criteria, for a longer time. IMHO, I get a tidier PES scan! Nevertheless, I will
not dare to say that Peter way of working isn't correct - I just don't use it.
Loose criteria means a less demanding convergence tolerance. But I'll try to use
his way just to compare with mine, and see what I get.
Best Regards,
Alcides