Reduction quantum mechanical

The Electronic Configuration Model, Quantum Mechanics and Reduction... 

The historical development of the electronic configuration model is traced and the status of the model with respect to quantum mechanics is examined. The successes and problems raised by the model are explored, particularly in chemical ah initio calculations. The relevance of these issues to whether chemistry has been reduced to quantum mechanics is discussed, as are some general notions on reduction. 

Electronic Configuration Model Quantum Mechanics and Reduction 311... 

Similarly the apparent success shown by orbital model as a zero order basis for the classification of spectral lines should not be taken to suggest a reduction of the chemical phenomena to quantum mechanics. 

Eric Scerri studied chemistry at the Universities of London, Cambridge and Southampton, and obtained a Ph.D. in the history and philosophy of science from King s College, London on the question of "The Reduction of Chemistry to Quantum Mechanics," He has been a research felloiu in the history and philosophy of science at the London School of Economics and at the California Institute of Technology. He is currently an assistant professor of chemistry at Bradley University, where he also teaches histoiy and philosophy of chemistry, which are also his main research interests. He is editor of the new journal Foundations of Chemistry. Address Department of Chemistry, Bradley University, Peoria, IL 61625. Internet scerri bradley.edu. 

Scerri, E. R. 1991. Electronic configurations, quantum mechanics and reduction. British Journal for the Philosophy of Science 42 309-325. 

It is indeed a great honor to be invited to contribute to this memorial volume. I should say from the outset that I never met Lowdin but nevertheless feel rather familiar with at least part of his wide-ranging writing. In 1986 I undertook what I believe may have been the first PhD thesis in the new field of philosophy of chemistry. My topic was the question of the reduction of chemistry to quantum mechanics. Not surprisingly this interest very soon brought me to the work of Lowdin and in particular his analysis of rigorous error bounds in ab initio calculations (Lowdin, 1965). 

Quantum mechanics is part of the reductionist tradition in modem science, and the general claim, often just made implicitly as in any branch of reduction, is that the highest ideal one can aspire to is to derive everything from the theoretical principles. The less experimental data one needs to appeal to, the less one is introducing measured parameters the purer the calculation and the closer it approaches to the ideal of Ockham s razor of being as economical as possible (Hoffman, Minkin, Carpenter, 1996).2... 

Rate of change of observables, 477 Ray in Hilbert space, 427 Rayleigh quotient, 69 Reduction from functional to algebraic form, 97 Regula fold method, 80 Reifien, B., 212 Relative motion of particles, 4 Relative velocity coordinate system and gas coordinate system, 10 Relativistic invariance of quantum electrodynamics, 669 Relativistic particle relation between energy and momentum, 496 Relativistic quantum mechanics, 484 Relaxation interval, 385 method of, 62 oscillations, 383 asymptotic theory, 388 discontinuous theory, 385 Reliability, 284... 

Excited state electron transfer also needs electronic interaction between the two partners and obeys the same rules as electron transfer between ground state molecules (Marcus equation and related quantum mechanical elaborations [ 14]), taking into account that the excited state energy can be used, to a first approximation, as an extra free energy contribution for the occurrence of both oxidation and reduction processes [8]. 

At present, new developments challenge previous ideas concerning the role of nitric oxide in oxidative processes. The capacity of nitric oxide to oxidize substrates by a one-electron transfer mechanism was supported by the suggestion that its reduction potential is positive and relatively high. However, recent determinations based on the combination of quantum mechanical calculations, cyclic voltammetry, and chemical experiments suggest that °(NO/ NO-) = —0.8 0.2 V [56]. This new value of the NO reduction potential apparently denies the possibility for NO to react as a one-electron oxidant with biomolecules. However, it should be noted that such reactions are described in several studies. Thus, Sharpe and Cooper [57] showed that nitric oxide oxidized ferrocytochrome c to ferricytochrome c to form nitroxyl anion. These authors also proposed that the nitroxyl anion formed subsequently reacted with dioxygen, yielding peroxynitrite. If it is true, then Reactions (24) and (25) may represent a new pathway of peroxynitrite formation in mitochondria without the participation of superoxide. 

In this study, identification of the critical atomic and molecular determinants pertaining to the mechanism of dihydrofolate to tetrahydrofolate reduction was achieved by (i) ab initio quantum mechanics, (ii) molecular mechanics, and (iii) free energy perturbation techniques. For the first time, the complete free energy profile was calculated for the proton transfer from Asp27 of the enzyme E. Coli DHFR to the N5 position of the dihydropterin moiety of the substrate dihydrofolate. In addition, the free... 

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