SPEC solves 3D magnetohydrodynamic (MHD) equilibria with stepped-pressure profiles. This powerful description doesn't artificially restrict the solution to nested flux surfaces, and admits simulations with islands and chaotic regions. It is a spectral-element code, that finds minimal-plasma-energy states by extremizing the multi-region, relaxed-MHD (MRxMHD) energy functional.

• There is a brief description of SPEC on the Princeton Plasma Physics Laboratory Theory Department website.
• An overview of the algorithm is given in a Flow Chart.
• A list of publications using SPEC are in our bibliography section
• Please direct questions/suggestions to Stuart Hudson.

If you use SPEC in your research, please cite it appropriately using the "Cite this repository" button on the right of the SPEC GitHub Repository or the CITATION.cff file.

Instructions for compiling and testing SPEC are in compilation_instructions.md.

Online documentation for SPEC is available on Github pages or in PDF form at SPEC_manual.pdf.