Update: Please refer to version2 of the code. We have made some changes in the code generating figure S5(Symmetric and anti-symmetric channel for radiated electric field) in the Supplementary material Code and datasets for the manuscript "Theory of Nonlinear Spectroscopy of Quantum Magnets". The codes and datasets for Main text and Supplementary mater are stored in separate folders. Instructions.doc is provided wherever necessary. Important: The codes generating datasets have been parallelised using joblib to use all cores available. If this is inconvenient for the user, the user must change num_cores in respective section of each code.