Reference for molecular orbital theory [duplicate]








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Closed 2 years ago.



I am studying electron collision with molecules, and came across with notation like this $\left(\mathrm{B}^{1} \Sigma\_{u}^{+}, \mathrm{c}^{3} \Pi\_{u}, \mathrm{a}^{3} \Sigma\_{g}^{+}, \mathrm{C}^{1} \Pi\_{u}\right)$ for the $H\_2$ molecules and I have no idea what they are.
Is there any textbook that explains what this symbols are?


