Effect of the generalized Breit interaction on the K-shell x-ray spectra of hot krypton plasmas

•K-shell x-ray spectra of hot krypton plasmas were simulated by using a collision-radiative model, for which the atomic parameters were generated by using the flexible atomic code (FAC).•Effects of the generalized Breit interaction (GBI) on the atomic parameters and the K-shell x-ray spectra of hot krypton plasmas have been investigated, and thus the GBI effect on the accuracy of the plasma diagnostics has been estimated.•This work will contribute to plasma diagnostics in fusion science, due to that the krypton is used as a tracer to obtain the temperature and density in the inertial confinement fusion experiments, and it is used as a coolant in magnetic confinement fusion experiments.