 Extended Hückel method

The Extended Hückel method (EHM) is a semi-empirical quantum chemistry technique used to estimate the electronic structure of molecules, particularly organic compounds and some inorganic systems. It is an extension of the original Hückel molecular orbital (HMO) theory, which was primarily developed for planar conjugated systems. The Extended Hückel method broadens this approach to accommodate three-dimensional systems and allows for a more accurate representation of interactions between atomic orbitals.