... application of the complete set of atomic orbitals. These requirements aretoo demanding.12.12.1 LONDON ORBITALSAtomic orbitals are used in quantum chemistry as the building blocks of many-electron ... sometimes representsa serious problem. On top of this, in the case of a magnetic field, there is, addi-tionally, the above mentioned arbitrariness of choice of the vector potential ori-gin. A remedy ... “Propagators in Quantum Chemistry , 2nd edition, John Wiley & Sons, Ltd,2004.81Thus, although calculation of the coupling constants is certainly complex, we have in mind a simplemodel of the nuclear...