For all triradicals in this study, the geometries are optimized in high-spin state employing the UB3LYP/def2-TZVP method. The high-spin state optimized geometries are used for further calculations. The calculations are accelerated by using the resolution-of-identity (RI) approximation in conjunction with the auxiliary basis set def2/J and chain of spheres (COSX) numerical integration technique. For DFT methods, energy gaps are computed by using the approximate spin-projection (AP) method as in Eq. 6. For CBS-DFT calculations, UB3LYP/6-31G(d) method is used. In addition to the DFT methods, to avoid the problem of spin-contamination and to access dynamical and non-dynamical electron correlations, wavefunction-based methods have been used. The state-averaged complete active space self-consistent field, i.e., SA-CASSCF and n-electron valence second-order perturbation theory (NEVPT2) calculations with def2/TZVP basis set are performed on the DFT highspin state optimized geometrical structures for CAS (3,3), CAS (5,5), CAS(7,7) and CAS (9,9) active spaces. For each active space, state-averaging uses one quartet and two doublet states with equal weights. For larger active spaces, the orbitals obtained from CAS(3,3) active space have been used as an initial guess. The triradical character, i.e., the degree to which the system pocesses three unpaired electrons localized on different moeities within the molecule, is quantified on the basis of natural orbital occupation numbers of CASSCF calculations.