The nonadiabatic coupling vector was calculated, combined with the automatic searches for minima on the crossing seam (MXS), at the multireference configuration-interaction (MR-CI). Its program was implemented into the COLOMBUS program system. A Lagrange formalism for the determination of MXS, based on a perturbative description of the vicinity of a conical intersection, was derived. The methods developed allow MXS searches of significantly larger systems at the MR-CI, level than before. The calculations were more accurate as compared to the previous complete-active space self-consistent field approaches (CASSCF).