Research Interests 1. Nonequilibrium Atomic Limit. Theoretical tools employed in ab initio simulations in the field of molecular electronics combine methods of quantum chemistry and mesoscopic physics. Traditionally these methods are formulated in the language of effective single-particle orbitals. We argue that in many cases of practical importance a formulation in the language of many-body states, the nonequilibirum atomic limit, is preferable. We work with generalized quantum master equation (QME), Hubbard and pseudoparticle nonequilibrium Green functions (NEGF) formulations as many-body states based alternatives to the standard Redfield QME and NEGF methodologies. 2. Molecular Optoelectronics. The interaction of light with molecular conduction junctions is attracting growing interest as a challenging experimental and theoretical problem on one hand, and because of its potential application as a characterization and control tool on the other. In particular, Raman spectroscopy (following inelastic electron tunneling spectroscopy) has the potential to become an important diagnostic tool very much needed in the field of molecular electronics. Raman scattering was utilized to judge the presence and extent of the heating of molecular vibrations. These experiments are motivation for our theoretical formulation of transport and Raman scattering in molecular junctions. We develop both model and ab initio formulations accounting for both optical scattering and electron transport on the same footing. 3. Molecular Nanoplasmonics. Research in plasmonics is expanding its domains into several subfields. The unique optical properties of the surface plasmon-polariton (SPP) resonance, being the very foundation of plasmonics, find intriguing applications in optics of nanomaterials, materials with effective negative index of refraction, direct visualization, photovoltaics, single-molecule manipulation, and biotechnology. We work on modeling molecule-plasmon interactions, an essential ingredient in any realistic ab initio simulation for optical response of molecular junctions or optically driven open nanoscale devices. 4. Molecular Spintronics. The possibility of constructing spin devices utilizing organic molecules was demonstrated in a number of experiments, indicating the emergence of molecular spintronics as a new branch of molecular electronics. Magnetic field and electric potential were considered in the literature as controls for spin flux. We study theoretically molecular devices where spin rather than charge flux is the measured signal. Of particular interest are spin fluxes manipulated by an external electric field.