Mass-radius diagram. The grey point represent all the exo-planets from the Extrasolar Planets Encyclopaedia (http://www.exoplanet.eu/) as of 1 March 2022, with masses and radii known with a precision better than 30%. HD 3167 b and c are represented in the different instrument passbands analyzed in this work (CHEOPS. K2, HST/WFC3/G141 and Spizer/IRAC/Ch2). The black dash-dotted lines indicate two iso-density profiles matching the planets b and c. The colored solid and dashed lines are indicative chemical compositions as computed by Zeng et al. (2019).