Working Note IV: Icosahedral Boundary Matching and Relaxation in Heterotypic Dual-Core (2D, 0D18, 0D6) Lattices

This technical memorandum records the boundary-matching conditions for a (2D, 0D18, 0D6) lattice configuration combining two heterotypic 0-dimensional point-support distributions (Bb = 18, Bc = 6) and one 2-dimensional complex planar element (Bs = 2) in the absence of 1-dimensional linear elements within a 3-dimensional Cosserat continuum. Applying the stationary condition of the Cosserat-projection action (delta Sproj = 0) and the Hessian subspace dimension ratio, we evaluate the 72-node forced-volumization friction (Gamma = +648), the prime and spin-excited gaps (+36, +72), and the icosahedral relaxation ratio (20/6 = 10/3).