Float' object is not iterable

I have error in recent version of psi4 1.1
The error says float object is not iterable when i perform optimization.
https://pastebin.com/gZ1UjyiK

@Rollin_King, should this happen? TORS::compute_val: unable to compute torsion value

I don’t see anything wrong with the calculation. Presumably, one of the bond angles contained within a dihedral definition is going near 180 degrees, but we can’t tell from this output. The default initial step of 0.5 au could be very large if concentrated in an angle. As a possible workaround, I suggest trying

INTRAFRAG_STEP_LIMIT = 0.2

You could also try

DYNAMIC_LEVEL = 1

so that the exception should trigger a definition of new internal coordinates if necessary. You could also try

OPT_COORDINATES = CARTESIAN

though this is more of a last resort. I will put this calculation into a test suite for future development.