Cannot determine mode alignment for a benzene structure in semp

[ntBre]

Panic occurs here:

pbqff/crates/spectro/src/lib.rs

Lines 590 to 600 in eb26513

	eprintln!(
	"lxm[(ncomp3, imode2)] = {}",
	lxm[(ncomp3, imode2)]
	);
	eprintln!(
	"lxm[(ncomp3, imode1)] = {}",
	lxm[(ncomp3, imode1)]
	);
	eprintln!("TOLER = {TOLER}");
	eprintln!("{self:#?}");
	panic!("cannot determine mode alignment")

Is there anything we can do besides panic? Presumably the root cause of the error is much earlier, probably in process_geom.

I've added some debug logging but don't have a good idea of the root cause. I'll need to find a reproducing test case to work on this.