Among all the Quantum Mechanics/Molecular Mechanics (QM/MM) methods available to describe large molecular systems, the Local Self-Consistent Field/MM (LSCF/MM) one uses frozen doubly occupied Strictly Localized Bonding Orbital (SLBO) to connect the QM fragment to the one treated at the MM level. This approach is correct as long as the QM part is large enough to minimize the artifacts that could...

In this paper, the frontier hybrid orbitals (FBO's) of a series of octahedral ML5 fragments are used to discuss the electronic structure and the chemical bond of these fragments and the molecules built of these ML5 fragments. The bond orbitals which are chosen as the linear combination of the frontier hybrid orbitals . of fragments are calculated and explain the electronic structure and propert...