These codes in fortran calculate the location in semimajor axis, libration centers and the strength of three body mean motion resonances of a particle with two planets or a system of planets taken by pairs. Both planets are not in mutual resonance, they are called pure three body resonances (not a chain of resonances). The particle can be located in an arbitrary position with respect to the planets. The model is given by Gallardo (2014, Icarus).

Given a planetary system the program atlas3bgeneral calculates all three body resonances in a given range of semimajor axes with all the planets taken by pairs. Planets are assumed in fixed circular and coplanar orbits and the test particle with arbitrary orbit. The file atlas3bgeneral.zip contains the source code in f77 and a sample input data file "massivebodies.inp" to calculate the three-body resonances. You need to compile with a fortran compiler. The executable and input data file must be in the same directory.

Note: pure three body resonances generally appear at low (e,i) because for large (e,i) values the two body resonances dominate the dynamics.

CODES HERE

Reference: Gallardo (2014, Icarus)

Three Body Resonance Locator (try it!)