The diamagnetic molecules are

$\begin{array}{l}{\mathrm{C}}_2-{\sigma }^{2}1\mathrm{s}<{\sigma }^{\ast }1{\mathrm{s}}^2<\sigma 2{\mathrm{s}}^2<{\sigma }^{\ast }2{\mathrm{s}}^2<\mathrm{\Pi }2{\mathrm{px}}^2\equiv \mathrm{\Pi }2{\mathrm{py}}^2\\ {\mathrm{N}}_2:\sigma 1{\mathrm{s}}^2\sigma 1{\mathrm{s}}^2\sigma 2{\mathrm{s}}^2\sigma 2{\mathrm{s}}^2\pi 2{{\mathrm{p}}_{\mathrm{x}}}^{\ast }=\pi 2{{\mathrm{p}}_{\mathrm{y}}}^2\pi 2{{\mathrm{p}}_{\mathrm{x}}}^2\\ {\mathrm{F}}_2:\sigma 1{\mathrm{s}}^2<{\sigma }^{\ast }1{\mathrm{s}}^2<\sigma 2{\mathrm{s}}^2<{\sigma }^{\ast }2{\mathrm{s}}^2<{\sigma }_{2{\mathrm{p}}_{{\mathrm{z}}^2}}<\\ {\mathrm{\Pi }}_{2{\mathrm{p}}_{{\mathrm{x}}^2}}\equiv {\mathrm{\Pi }}_{2{\mathrm{p}}_{{\mathrm{y}}^2}}<{\mathrm{\Pi }}_{2{\mathrm{p}}_{{\mathrm{x}}^2}}\equiv {{\mathrm{\Pi }}^{\ast }}_{2{\mathrm{p}}_{{\mathrm{y}}^2}}<{{\sigma }^{\ast }}_{2{\mathrm{p}}_{2^0}}\end{array}$