A Gauge Invariant Multiscale Approach to Magnetic Spectroscopies in Condensed Phase: General Three-Layer Model Computational Implementation and Pilot Applications

摘要

Analytical equations to calculate second order electric and magnetic properties of a molecular system embedded into a polarizable environment are presented. The treatment is limited to molecules described at the self consistent field (SCF) level of theory, including Hartree–Fock theory as well as Kohn-Sham density functional theory (DFT) and is extended to the Gauge-Including Atomic Orbital method (GIAO). The polarizable embedding is described by means of our already implemented polarizable QM/MM methodology, where the polarization in the MM layer is handled by means of the fluctuating charge (FQ) model. A further layer of description, i.e, the polarizable continuum model, can also be included. The FQ(/PCM) contributions to the properties are derived, with reference to the calculation of the magnetic susceptibility, the NMR shielding tensor, EPR g-tensors and hyperfine couplings.