Quantum chemistry reductionism

Contents Open Problems of the Present-Day Theoretical Chemistry. - On the Structure of Scientific Theories. - Pioneer Quantum Mechanics and its Interpretation. - Beyond Pioneer Quantum Mechanics. - A Framework for Theoretical Chemistry. - Reductionism, Holism and Complementarity. - Bibliography and Author Index. - Index. 

Foremost in the analysis of the authors who deal with theoretical and quantum chemistry is the physical reductionism of chemistry seen from the perspectives of the chemists involved, and the competitive evolution of research schools in the various political systems of the United States, the United Kingdom, France, Italy, and Germany at mid-century. In his introduction, Nikos Psarros from a philosoph-... 

In this paper we discuss a number of issues which manifest the theoretical particularity of quantum chemistry and which are usually not discussed in an explicit manner either in the historical or in the philosophical studies related to quantum chemistry. We shall focus on five issues the re-thinking of the problem of reductionism, the discourse of quantum chemistry as a confluence of the traditions of physics, chemistry, and mathematics, the role of textbooks in consolidating this discourse, the ontological status of resonance, and the more general problem of the status of the chemical bond. Finally, we shall briefly discuss the impact of large scale computing. 

Through its ups and downs, the concept of orbital hybridization is most significative for the perspectives opened out by Quantum Chemistry from about 1930. Let us only mention all the disputes in which it was involved during almost one century with regard to tricky questions of molecular structure (i.e., the supremacy of valence-bond pictures over molecular orbitals or vice-versa, the physical content of the resonance theory, the localization versus delocalization dilemma and so on...). Furthermore, its study gives us a good example of the specificity of the scientific explanation among chemists (i.e., the rejection of reductionism to Physics [1]). 

Tunnelling up, on the other hand, there is the objection that chemistry as a subject is overall too complex for reductionism where quantum chemistry cannot predict accurately real world phenomena—take, for example, the chemical similarity of vanadium and niobium which have different electronic structures [27, 29]. The same argument can be made against simulations that rely on interatomic potentials rather than electronic structure calculations in either case the simulation will be too abstracted, too reduced from reality, to be useful. 

We have insisted throughout the book that what we want to articulate is not the philosophical considerations of reductionism, the discussion of which in the case of quantum chemistry, and thus quantum mechanics, has been greatly enriched by contributions of Hans Primas (1983, 1988), Jeff Ramsey (1997), Eric Scerri (2007), and J. van Brakel (2000), among others, but rather the ways it has marked the culture of quantum chemists, the way the awareness of such a problem by the community of (quantum) chemists—in naive philosophical terms—permeated their practices. Though a number of them had expressed their "worries," reductionism in any of its variants was certainly not a paralyzing factor. Perhaps, one of the intriguing aspects of reductionism is that much of the discussion depends on the theoretical framework with respect to which such a discussion is realized. But, how has this problem appeared in the context of another theory in chemistry, that of chemical thermodynamics What... 

Perhaps philosophers of chemistry have a role to play here. Unconstrained by what can presently be achieved, or even what might be achieved in the foreseeable future, one can point out the limitations of the current state of the art and one can place the research in the wider context of scientific reductionism in general and what it might mean for a calculation to be really ab initio. This is not a denial of the progress achieved in quantum chemistry or a reproach of the current work. It is more of an unrestrained look at what more could conceivably be done. Of course this might require a deeper theory than quantum mechanics or maybe a cleverer use of the existing theory. There is really no way of telling in advance. 

Primas, 1981] H. Primas. Quantum Chemistry and Reductionism, Lecture Notes in Chemistry 24, Springer-Veriag, Berlin, 1981. 

Primas, H. Chemistry, Quantum Mechanics and Reductionism Springer Berlin,... 

Vol. 24 H. Primas, Chemistry, Quantum Mechanics and Reductionism. Xll, 451 pages. 1981. (out of print) 2nd edition, ISBN 3-540- 12838-7... 

The question of reductionism has been reigning supreme in any discussions concerning the philosophical, theoretical, methodological and many times historical aspects of chemistry. In 1929, Paul A. M. Dirac, after he had successfully incorporated the spin quantum number into the newly developing quantum mechanics, expressed what every physicist felt to be true and what every chemist was afraid that it might be true. 

Primas, Hans. 1983. Chemistry, Quantum Mechanics, and Reductionism. Berlin Springer-Verlag. 

According to Primas (1991, p. 163), "the philosophical literature on reductionism is teeming with scientific nonsense," and he quotes, among others, Kemeny and Oppenheim (1956), who said "a great part of classical chemistry has been reduced to atomic physics." Perhaps it was not philosophers who invented this story after all. Almost certainly, Oppenheim and other philosophers of science at the time were familiar with the influential statements of Dirac, Heisenberg, Reichenbach, and Jordan on this issue. " Notoriously, the physicist Dirac (1929, p. 721) said, the underlying laws necessary for the mathematical theory of a large part of physics and the whole of chemistry are thus completely known, and the difficulty is only that exact applications of these laws lead to equations which are too complicated to be soluble." Less famously, the philosopher of science Reichenbach (1978, p. 129) reiterated that "the problem of physics and chemistry appears finally to have been resolved today it is possible to say that chemistry is part of physics, just as much as thermodynamics or the theory of electricity." These views clearly stuck. For example, in a recent review of quantum electrodynamics (QED), to which Dirac made important contributions, the historian of science Schweber (1997, p. 177) says, "the laws of physics encompass in principle the phenomena and the laws of chemistry."... 

Prelat, C. E. 1947. Epistemologia de la quimica. Buenos Aires Espasa and Calpe Argentina. Primas, H. 1983. Chemistry, Quantum Mechanics and Reductionism. Berlin Springer. 

Primas H (1981) Chemistry, quantum mechanics and reductionism perspectives in theoretical chemistry, vol 24. Lecture Notes in Chemistry, Springer Verlag, Berlin... 

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