The radial Hamiltonian for the ground electronic state of KrH+.

All literature vibration-rotational and pure rotational transitions belonging to ten isotopomers of KrH+ in the X'sigma+ state (in total 351 lines) have been used in a iterative nonlinear least-squares fit of compact analytic Born-Oppenheimer potential in the form of generalized potential energy function (GPEF). Additional functions describing the adiabatic and nonadiabatic corrections have also been determined. The obtained radial Hamiltonian reproduces the spectra with sufficiently good accuracy. The GPEF of KrH+ reproduces the experimental value of the dissociation energy, has a correct R(-4) asymptotic behaviour, and reproduces long-range inverse-power potential coefficient C4.