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In order to know the electronic and magnetic struc- tures of the compound we have carried out FM calcu- lation. The energy of the FM solution is found to be ∼ 336 meV less than that of nonmagnetic solution in- dicating the ferromagnetic ground state for the system. This result is in accordance with the experimental obser- vation and earlier theoretical calculations. 3,5 The total and partial density of states obtained for the FM config- uration are plotted in Fig. 3. There is an asymmetric distribution of states in both the spin channels. The dif- ference between number of electrons in up and down spin channels is a measure of net magnetization and found to be ∼ 2. Under the rigid band picture one can estimate the effective value of the exchange parameter ( J ) by con- sidering the energy difference between the up and down band edges, which is estimated to be ∼ 0.4 eV. The t$_{2}$$_{g}$ up-spin bands are fully occupied whereas t$_{2}$$_{g}$ down-spin and e$_{g}$ bands are partially occupied. 

Similar to the nonmagnetic case, e$_{g}$ bands are highly extended in comparison to t$_{2}$$_{g}$ bands. The strength of ex- change parameters for t$_{2}$$_{g}$ and e$_{g}$ electrons are estimated 

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to be ∼ 0.6 and 0.4 eV, respectively. The larger value of J for t$_{2}$$_{g}$ electrons can be attributed to more localized t$_{2}$$_{g}$ states leading to higher Coulomb interaction. Inter- estingly, O 2 p PDOS also show spin polarization and the estimated value of J for p electrons is also found to be ∼ 0.4 eV. The values of magnetic moment for Co, O1 and O2 atoms are found to be about 1.52, 0.17 and 0.07 µ$_{B}$ , respectively. The total magnetization per formula unit is ∼ 2 µ$_{B}$ , which is almost same to the earlier reports. 3,5 The appearance of magnetic moments at the O sites may be attributed to the strong hybridization between d$_{x}$ $^{2}$− y 2 and O1 ( p$_{x}$ , p$_{y}$ ) orbitals; and d$_{z}$ $^{2}$− r 2 and O2 p$_{z}$ orbitals. The values of magnetic moment for O1 and O2 atoms also appear to support this conjecture as the magnetic moment of O1 is roughly 2 times larger than that of O2. 

In order to know the role of orbital degrees of free- dom on the magnetic properties of the system we have included SOC in the calculations by considering magneti- zation directions along (001) and (100) axes. Our calcu- lations indicate that the c -axis is an easy axis as the total energy of the system for (001) direction is found to be ∼ 2.7 meV/Co less than that for (100) direction. This result 

