We cast crystal diffraction as a boundary value problem with Maxwell-Schr\"odinger equation as the governing partial differential equation.Unitcell defined boundary conditions determine definite momentum eigen series in spherical basis to include precision angles as additional data measurable in a stationary spherical polar polar coordinate system with polar axis always aligned along direct beam in the experiment.
Orbital structure of individual atoms is contained in angle dependence and thus in the precision angles of position and momentum vectors.
Partial wave version of Parseval relation becomes probability conservation law.
We show that polar angles and azimuthal angles respectively determine signs and phases of partial wave sub-amplitudes and give rise to solution to phase problem.