Here you can download my exact Riemann solver for relativistic MHD (Bruno Giacomazzo and Luciano Rezzolla 2006, Journal of Fluid Mechanics, 562, 223). The solver can be also downloaded from the program section of “Grid-based Methods in Relativistic Hydrodynamics and Magnetohydrodynamics”.
This exact solver can provide exact solutions for Riemann problems in relativistic MHD using both an ideal fluid EOS and a Synge-type EOS (Meliani et al 2008). This is the first exact Riemann solver able to solve any Riemann problem in RMHD. The solutions computed by this code have been used by several numerical relativity groups to test their codes or to describe the physics of relativistic plasmas.
The code is available for download on GitHub: https://github.com/bgiacoma/Exact_Riemann_Solver.git
Here you can download the exact solutions to some of the most common problems.
Below you can also find a map of some of the places where it has been used. If you see a mistake or if a place is missing, simply contact me. Thanks!