Displaced core-shell ellipsoid model - absolute scale version

This model calculates the scattering intensity from core-shell ellipsoids where the core centre is displaced relative to the shell centre. This model is identical in geometry and physics to ``core_shell_displ_core``,but works in **absolute scale** (cm\ :sup:`-1`). Instead of a dimensionless contrast ratio, the user supplies the scattering length densities (SLDs) of the core, shell, and solvent directly, together with the particle volume fraction. The model then computes all contrasts internally and returns the absolute intensity without any additional ``scale`` factor.

Example Data: