I was curious about the use case of setting
OPT_COORDINATES: BOTH. Does this mean that it tries to work in internal to be faster but if it encounters an error, e.g. I used to see a torsion angle issue in older versions, it switches to cartesian to finish the calculation or does it have a different behaviour?
Any clarification would be greatly appreciated.
All the best
I’m pretty sure it just uses both. That means many coordinates are redundant, but we can still use them.
@AlexanderH would know for sure.
"opt_coordinates": "both" uses a full set of (3N-5/6) or more internal coordinates and 3N Cartesian coordinates. The combination has been found useful by some for molecules with many floppy modes. Currently, setting
'dynamic_level': 1 will allow for switching from internals to cartesians automatically during an optimization. As a disclaimer this will also allow
step_type and trust region options to be changed, during the optimization, differently than in the default RFO algorithm.