Comparing the magnetic coupling (J-values) derived from singlet and septet energies, the LASSIS and LASSIS-PDFT methods show deviations of only 0.8 and 8.8 cm -1 from the reference values, respectively. Furthermore, the J-values for successive spin states are also within 3 cm -1 of each other (summarized in SI Table ), indicating minimal deviation and consistent performance of our methods. However, these values are still far from the experimental values. We hypothesize that is because of missing orbital relaxation for individual spin states. To test this hypothesis, we have performed DMRGSCF and DMRGSCF-PDFT calculations with M=1000, and the same active space and basis set. We optimized the orbitals for the septet state using DMRGSCF, and used them to calculate the energies of the other spin-states. In this case, the J-value (using S = 0, and S = 3) at the DMRGSCF and DMRGSCF-PDFT levels are -26.1 and -46.6 cm -1 respectively, on optimization for each spin-state, the magnitude of J predicted by DMRGSCF-PDFT increased substantially to -70.0 cm -1 (essentially reproducing Ref. 39, as anticipated). This suggests that reoptimizing the orbitals for the LASSIS wave functions corresponding to various spin-states would also significantly increase the magnitude of the LASSIS-PDFT Jvalue. The LASSIS orbital reoptimization is a potential promising avenue of development for future work.