Experimental Considerations Techniques and Molecular Systems

The spectroscopy and dynamics of photosynthetic bacterial reaction centers have attracted considerable experimental attention [1-52]. In particular, application of spectroscopic techniques to RCs has revealed the optical features of the molecular systems. For example, the absorption spectra of Rb. Sphaeroides R26 RCs at 77 K and room temperature are shown in Fig. 2 [42]. One can see from Fig. 2 that the absorption spectra present three broad bands in the region of 714—952 nm. These bands have conventionally been assigned to the Qy electronic transitions of the P (870 nm), B (800 nm), and H (870 nm) components of RCs. By considering that the special pair P can be regarded as a dimer of two... 

Molecular dynamics (MD) simulations are a class of molecular mechanics calculation which directly model the motions of molecular systems, often providing considerable information which cannot be obtained by any other technique, theoretical or experimental. MD simulations have only recently been applied to problems of carbohydrate conformation and motions, but it is likely that this technique will be widely used for modeling carbohydrates in the future. This paper introduces the basic techniques of MD simulations and illustrates the types of information which can be gained from such simulations by discussing the results of several simulations of sugars. The importance of solvation in carbohydrate systems will also be discussed, and procedures for including solvation in molecular dynamics simulations will be introduced and again illustrated from carbohydrate studies. 

An excited state structural analysis [23] was conceived within r-electron model as a response to the experimental evidence of localization phenomena in excited molecules. Thirty years after it was revived in a new (TDDFT) clothing [17] that allows one to extend the approach to a more realistic quantum-chemical description. Now equipped with this revitalized technique, we tried here to elucidate how ESSA, more exactly ESSA/TDDFT, works on complex molecular systems. Before summing up, several critical remarks need to be made. They are related to the current status of DFT and TDDFT in particular, and encompass issues too difficult to permit anything but a preliminary and inevitably very sketchy consideration. 

Contents Experimental Basis of Quantum Theory. -Vector Spaces and Linear Transformations. - Matrix Theory. -- Postulates of Quantum Mechanics and Initial Considerations. - One-Dimensional Model Problems. - Angular Momentum. - The Hydrogen Atom, Rigid, Rotor, and the H2 Molecule. - The Molecular Hamiltonian. - Approximation Methods for Stationary States. - General Considerations for Many-Electron Systems. - Calculational Techniques for Many-Electron Systems Using Single Configurations. - Beyond Hartree-Fock Theory. 

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