$N _2$

$\sigma 1 s ^2 \sigma^* 1 s ^2 \sigma 2 s ^2 \sigma^* 2 s ^2 \pi 2 p _{ x }^2=\pi 2 p _y^2 \frac{\sigma 2 p _z^2}{\text { HOMO }}$

$N _2^{+}-\sigma 1 s ^2 \sigma^* 1 s ^2 \sigma^* 2 s ^2 \sigma^* 2 s ^2 \pi 2 p _{ x }^2=\pi 2 p _{ y }^2 \frac{\sigma 2 p _z^1}{\text { HOMO }}$

$O _2-\sigma 1 s ^2 \sigma^* 1 s ^2 \sigma 2 s ^2 \sigma^* 2 s ^2 \sigma 2 p _z^2$

$\pi 2 p _{ x }^2=\pi 2 p _{ y }^2$

$\pi^* 2 p _{ x }^1=\pi^* 2 p _{ y }^1( HOMO )$

$O _2^{+}-\sigma 1 s ^2 \sigma * 1 s ^2 \sigma 2 s ^2 \sigma * 2 s ^2 \sigma 2 p _z^2 \pi 2 p _{ x }^2=\pi 2 p _y^2$

$\pi^* 2 p _{ x }^1=\pi^* 2 p _{ y }^0( HOMO )$

$N _2 \Rightarrow 0 \text { unpaired } e ^{-} \text {in HOMO }$

$N _2^{+} \Rightarrow 1 \text { unpaired } e ^{-} \text {in HOMO }$

$O _2 \Rightarrow 2 \text { unpaired } e ^{-} \text {in HOMO }$

$O _2^{+} \Rightarrow 1 \text { unpaired } e ^{-} \text {in HOMO }$