Closed-form evaluation of the Lieb 1967 6-vertex anisotropy Δ = (a²+b²-c²)/(2ab) at three canonical points. Ice point (Pauling 1935 water-ice model, a = b = c = 1): Δ = 1/2 exactly — sits in the massless regime |Δ| < 1, mapping to the…
Closed-form evaluation of the Lieb 1967 6-vertex anisotropy Δ = (a²+b²-c²)/(2ab) at three canonical points. Ice point (Pauling 1935 water-ice model, a = b = c = 1): Δ = 1/2 exactly — sits in the massless regime |Δ| < 1, mapping to the…