The reduced Planck constant is measured, never derived, in standard physics. This paper derives it from the geometry of matter condensation out of a physical substrate, using only the proton mass, the proton radius, the speed of light, and one geometric ratio.
The derived value matches the measured constant to 0.0001 percent. The Compton wavelength, de Broglie relations, and spin one-half angular momentum then follow from the same geometry.