In quantum chemistry he worked on semi-empirical molecular orbital theory and settling conjugated-circuit model on a firm quantum-mechanical basis.
32.
He realised that the then current approach to molecular orbital theory was incorrect and changed his topic to what resulted in the development of the Roothaan equations.
33.
The impact of valence theory declined during the 1960s and 1970s as molecular orbital theory grew in usefulness as it was implemented in large digital computer programs.
34.
A 2 + 2 cycloaddition reaction is one example of a pericyclic reaction that can be analyzed using these rules or by the related frontier molecular orbital theory.
35.
For a discussion of frontier molecular orbital theory of 1, 3-dipolar cycloadditions, see 1, 3-dipolar cycloaddition # Frontier molecular orbital theory.
36.
For a discussion of frontier molecular orbital theory of 1, 3-dipolar cycloadditions, see 1, 3-dipolar cycloaddition # Frontier molecular orbital theory.
37.
Likewise, Molecular Orbital Theory, sort of a " hybridization theory on steroids ", makes a perfect prediction of the " correct " structure of benzene.
38.
In 1927 Mulliken worked with Hund and as a result developed his molecular orbital theory, in which electrons are assigned to states that extend over an entire molecule.
39.
The model determined by molecular orbital theory indicates that the bonds between boron and the terminal hydrogen atoms are conventional 2-center, 2-electron covalent bonds.
40.
In parallel, molecular orbital theory was applied in a more approximate manner using some empirically derived parameters in methods now known as semi-empirical quantum chemistry methods.
