Here the data related to our recent work that uses metasurfaces designed on metamaterials to excite Fano resonances and Rabi Split analogue modes for sensing. In this repository the following data are available: The Reflectance, Transmittance and Absorbance (1-T-R) evaluated over all the diffraction angles (from 0° to 89°) for the proposed structure (ring + cross) and the other tested structures, available in the .mat file. The .m file to repeat all the simulations are available in main folder. The available Matlab codes allow reproducing numerical simulations using Reticolo (RCWA) as the main framework to do the computation. Use "getrefractiveindex.m" to interpolate refractive index on finest wavelength range. Please, note that according to the uploaded codes this function have to be in the same folder of the loaded refractive indices. You can use the function "textprogressbar.m" to get a progress bar in real time to know the status of the current simulation. Please, note that this function have to stay in the "/RETICOLO V8/reticolo_allege" folder. One of the available Matlab code allows displaying the electric and magnetic field evaluated in the structure section or on the top view. The sensing test performed for the reported structures using different surrounding medium, for this purpose it is possible to use the codes that allow studying the parameters variation, the incident angle variation or just a single run changing the refractive index of the surrounding medium. The proposed code works using the Reticolo main code. To download it please visit the following link https://www.lp2n.institutoptique.fr/light-complex-nanostructures or using Zenodo https://zenodo.org/record/5905381#.Y8rvbC9abpA Once Reticolo has been downloaded copy and paste its path in the proposed Matlab code for Fano resonances on ENZ cavities as reported in the example codes. In this repository you will find the refractive indices that have been used.