covalent bond computational chemistry bond order quantum chemistry
Abstract:
We survey previous work on quantum mechanical definitions of bond order between two atoms in a molecule and discuss how the definitions are related. We discuss a definition applicable to single-determinant \textit{ab initio} wavefunctions. This definition has a clear physical interpretation in terms of correlated charge fluctuations. The basis set issues of previous methods such as the Wiberg and Mayer bond orders are resolved by using intrinsic atomic orbitals. A formula in terms of density matrices is given for calculating the bond order in practice. Bond orders calculated using the new definition are compared to those calculated using previous definitions.
