Magnetic shielding Approximation theory Coulomb and Breit two-body interaction operators Differential equations Eigenvalues and eigenfunctions Fermi contact Ground state Hamiltonians Magnetic molecular properties Magnetic potential Matrix algebra No-pair approximation Nuclear magnetic shielding tensor Perturbation techniques Schrodinger molecular energy Spin-other orbit interactions State space methods Tensors CEROS POR CAMINOS DIFFRACTION DIFFRACTION GRATINGS DIFRACCION HAMILTONIANO TIGHT BINDING MICROONDAS MICROWAVES MULTIPATH ZEROES POLARIMETRIA POLARIMETRY QUANTUM TRANSPORT RADAR DE APERTURA SINTETICA