frontier molecular orbital analysis

directory of Chem Help ASAP videos: https://www.chemhelpasap.com/youtube/ The output files in MO theory models can be very complex with many molecular orbitals. Fortunately, the reactivity of many molecules can be reduced to the properties of just two orbitals - the highest occupied molecular orbital (HOMO) and lowest unoccupied molecular orbital (LUMO). In the output file, the HOMO can be found by taking the number of valence electrons in the molecule and dividing by 2. That number is the MO number of the HOMO. The LUMO is the next highest MO number. The idea of focusing on the HOMO and LUMO is called frontier molecular orbital theory (FMO theory). The reactivity of molecules is often described in terms of nucleophilicity or basicity and electrophilicity or acidity. The properties of the HOMO determine nucleophilicity, and the LUMO drives electrophilicity.