By properly setting up the calculation of fragments and combining their occupied orbitals as promolecule wavefunction in a suitable way, sobEDA can be used for a rich variety of systems, including studying interaction between open-shell fragments. For example, by using sobEDA to study the interaction between CH3 and NH2 free radical fragments in CH3NH2, the neutral doublet state of the two fragments should be calculated separately. When combining the fragment wavefunctions, the information of alpha and beta orbitals of one of the fragments should be exchanged with each to generate the appropriate promolecule wavefunction. After that, when constructing the frozen state wavefunction, the orthogonalization should be performed separately for occupied orbitals of each spin.