It works for some systems, but not for all; such as FCl…CH2. I don’t know what to do. I have mentioned C2v symmetry which is followed through the optimization. the optimized structure should maintain C2v symmetry too. in this regard the <FClC is 180d, but the bond length is wrong. It shows r(F-Cl)=1.9A, while r(C-Cl)=1.6A.
Probably scanning the bond length along F-Cl…C might help. But it seems tough, trying to do so