Fig. 6. (a) LF splitting in the NdN molecule computed at the CASSCF/RASSI level as a function of the Nd–N distance and the sum of B₀², B₀⁴, and B₀⁶ contributions to the total LF splitting (cyan spheres with the dashed curve and the scale on the right side); (b) LF splitting in the NdN molecule computed with the point charge model and scaled LoProp atomic charge of N at the same Nd–N distances as in (a); (c) 4f-electron density in Nd–N built upon orbitals from CASSCF(3, 7) calculations, and concentric isosurfaces are plotted at the values of (from inner to outer) 0.25, 0.05, 0.01, and 0.002 a.u.; to guide the eye, the rightmost figure shows a circle centered on the Nd atom and plotted with the gray dashed line.