Global electromagnetic resonances within the Earth-ionosphere cavity - historically formalized as isotropic Schumann resonances - exhibit systematic frequency deviations that continuous wave mechanics attributes to complex ionospheric conductivity profiles . This paper provides a purely structural, non-singular alternative by analyzing global wave modes within a stationary, compressed Hexagonal Close-Packed (3HCP) space matrix. By replacing continuous spherical boundary conditions with a discrete 144-harmonic finite-difference network, we model the planet-ionosphere shell as a bounded discrete domain governed by an invariant coordination number Z = 12 . Through a multivariable Taylor series expansion, we establish a rigorous mathematical bridge proving that this 144-harmonic difference scheme converges identically onto the continuous spherical Laplacian and classical isotropic wave equations as the physical lattice parameter approaches zero (h -> 0). Crucially, under local hydrostatic compaction driven by the planet's gravitational boundary confinement, the horizontal entries of the Dynamic Electro-Leeway Tensor contract asymmetric to the vertical stacking axis . This structural anisotropy shifts the derived Markov Viscosity Tensor, causing a lifting of the geometric degeneracy of the wave operator . The unperturbed fundamental mode (f0 approx 7.83 Hz) undergoes a clean directional tri-splitting into autonomous spatial frequencies (fx, fy, fz) . The model completely accounts for observed diurnal frequency variations purely from first-principles discrete lattice deformations, exposing continuous field resonance profiles as smoothed, macro-statistical interpolations of underlying integer-driven network operations. Creative Commons Attribution Non Commercial No Derivatives 4.0 International