  We solved the instantaneous Bethe-Salpeter equation for heavy pseudoscalars
in different kernels, where the kernels are obtained using linear scalar
potential plus one gluon exchange vector potentials in Feynman gauge, Landau
gauge, Coulomb gauge and time-component Coulomb gauge. We obtained the mass
spectra of heavy pseudoscalars, and compared the results between different
kernels, found that using the same parameters we obtain the smallest mass
splitting in time-component Coulomb gauge, the similar largest mass splitting
in Feynman and Coulomb gauges, middle size splitting in Landau gauge.
