The conservation of their symmetry is the basis of the Woodward-Hoffman rules.
The innermost of these entities are assumed to be completely filled in the frozen core approximation. The changes in their energies due to changes in geometry are depicted in Walsh diagrams. In certain cases, their energies can be approximated in terms of exchange, Coulomb, and overlap integrals. The conservation of their symmetry is the basis of the Woodward-Hoffman rules. According to (*) Fukui, who developed their namesake "frontier" theory, chemical reactivity only depends on the highest occupied and lowest unoccupied examples of them. They always come in pairs, with the higher-energy one marked with a star and designated as "antibonding." For 10 points, name these functions that can be calculated as linear combinations of atomic orbitals.
The innermost of these entities are assumed to be completely filled in the frozen core approximation.
{molecular orbitals} [or {MOs,} prompt on "orbitals," I guess prompt on "wavefunctions" until "frontier"]