X+ is a computer program that can model multilayer single geometry-based structures that may also be in Space-Filling lattices.
The geometries include rectangular cuboids, a stack of layered structures, multiple spherical shells, concentric hollow cylindrical or distorted cylindrical structures, or a series of coaxial shifted helical structures.
Each layer or subunit has an electron density profile that can be uniform, Gaussian, or a sum of hyperbolic tangents.
The features of X+ include phase fitting algorithms to obtain lattice parameters and peak indices, model resolution function, and sample polydispersity. The range of models that X+ can compute is limited. Geometrical models can fit low-angle X-ray scattering data (corresponding to relatively low-resolution information in real-space).
X+ is described in our paper.
From more advanced modeling software check our state-of-the-art program D+.