What does the 'orbital approximation' in molecular orbital theory state?

The orbital approximation in molecular orbital theory posits that the total wave function of a multi-electron system can be expressed as a product of the wave functions of individual electrons, treating each electron's behavior within the context of an effective potential created by the other electrons and nuclei. This approximation simplifies the complex many-body problem into a more manageable form, allowing for the description of molecular orbitals as combinations of atomic orbitals.

By using this product form, one can calculate the properties of the molecule and make predictions about its behavior, such as bonding and electronic configuration. In this way, the orbital approximation facilitates a clearer understanding of molecular structure by treating the wave functions of electrons as one-electron functions that contribute to the total wave function, making it highly relevant in predicting and explaining molecular properties in inorganic chemistry.