IV.R144 — Mode-repulsion geometry

Molecular geometry follows from mode-repulsion: k winding-mode pairs on T^2 maximize minimum angular separation, yielding k=2 linear (180 deg), k=3 trigonal planar (120 deg), k=4 tetrahedral (109.5 deg), k=5 trigonal bipyramidal, k=6 octahedral; the symmetry depends only on k, not on iota_tau.