The calculated magnetic moments (spin only value) for species \( [\mathrm{FeCl_4}]^{2-} \), \( [\mathrm{Co(C_2O_4)_3}]^{3-} \) and \( \mathrm{MnO_4^{2-}} \) respectively are:
\( 5.92 \), \( 4.90 \) and \( 0 \) \( \mathrm{BM} \)
\( 5.82 \), \( 0 \) and \( 0 \) \( \mathrm{BM} \)
\( 4.90 \), \( 0 \) and \( 1.73 \) \( \mathrm{BM} \)
\( 4.90 \), \( 0 \) and \( 2.83 \) \( \mathrm{BM} \)