In zeolite pores, a confinement effect that acts primarily upon this entity reduces the gap between it and its counterpart.  The ionization potential of a closed-shell system may be determined by ascertaining the negative of its energy, a relationship described by Koopman's theorem. Walsh's rule predicts that molecular structures are predicated on the stability of these, while in ring-opening electrocyclic reactions, thei
In zeolite pores, a confinement effect that acts primarily upon this entity reduces the gap between it and its counterpart.  The ionization potential of a closed-shell system may be determined by ascertaining the negative of its energy, a relationship described by Koopman's theorem. Walsh's rule predicts that molecular structures are predicated on the stability of these, while in ring-opening electrocyclic reactions, their symmetry directs the symmetry of the newly formed p-orbitals.  Lewis bases have a lone pair of electrons in this region, and the photochemical induction of cycloaddition of ethylene is activated by excitement of a pi electron that migrates to enter a new one of these. The Diels-Alder reaction involves interaction between this orbital of the diene and the opposite orbital of the dienophile.  For 10 points, name this frontier orbital that contains at least one electron.
In zeolite pores, a confinement effect that acts primarily upon this entity reduces the gap between it and its counterpart.  
HOMO or highest occupied molecular orbital