Values of the Lande g factors are obtained for the first time for rovibronic levels of the (3d)J1Δg− state of the D2 molecule and of the (4d)S1Δg− state of the H2 and D2 molecules. Semiempirical values of these quantities are obtained for the first time for the (4d)R1Πg− state of the H2 molecule and the (3d)I1Πg− and (4d)R1Πg− states of the D2 molecule. These values are determined in terms of the nonadiabatic model, which takes into account the interaction between the ndπ1Πg and ndδ1Δg (n = 3 and 4) states in the approximation of pure precession, with the use of the semiempirical values obtained by us for the expansion coefficients of wave functions in the adiabatic basis functions and the results of our numerical calculation of overlap integrals of the vibrational wave functions of these states. The values thus obtained are in good agreement with the data available in the literature. It is found that the interference effects of coupling of the ndπ1Πg and ndδ1Δg states lead to significant perturbations of the dependences of the g factors of vibronic levels on the rotational quantum number as compared to the adiabatic results. These perturbations are regular (reaching a factor of nine) for the I1Πg− and R1Πg− states and irregular (reaching a factor of 50) for the J1Δg− and S1Δg− states. The nonadiabatic values of g factors obtained in our previous studies for the H2, HD, and D2 molecules in the i3Πg− and j3Δg− states are improved by an additional inclusion of adiabatic effects. It is established that the effect of the electron spin on the g factor values for rovibronic levels of the 3dΔg− states is significant and reaches 25% for H2 and 130% for D2.