This paper first queries what type of concept of emergence, if any, could be connected with the different chemical activities subsumed under the label ‘quantumchemistry’. In line with Roald Hoffmann, we propose a ‘rotation to research laboratory’ in order to point out how practitioners hold a molecular whole, its parts, and the surroundings together within their various methods when exploring chemical transformation. We then identify some requisite contents that a concept of emergence must incorporate in order to (...) be coherent from the standpoint of the scientific practices involved. In this respect, we finally propose a relational form of emergence which pays attention to the constitutive role of the modes of intervention and to the co-definition of the levels of organization. No metaphysical distinction between the higher and basic levels of organization is supposed, but only a plurality of modes of access. Moreover, these modes of access are not construed as mere ways of revealing intrinsic patterns of organization but, on the contrary, are considered to be active elements on which the constitution of those patterns depends. What is at stake in this paper is therefore not an ontological form of emergence but an agnostic one which fits what chemists do in their daily work. (shrink)
In this paper I expand Eric Scerri’s notion of Popper’s naturalised approach to reduction in chemistry and investigate what its consequences might be. I will argue that Popper’s naturalised approach to reduction has a number of interesting consequences when applied to the reduction of chemistry to physics. One of them is that it prompts us to look at a ‘bootstrap’ approach to quantumchemistry, which is based on specific quantum theoretical theorems and practical considerations that (...) turn quantum ‘theory’ into quantum ‘chemistry’ proper. This approach allows us to investigate some of the principles that drive theory formation in quantumchemistry. These ‘enabling theorems’ place certain limits on the explanatory latitude enjoyed by quantum chemists, and form a first step into establishing the relationship between chemistry and physics in more detail. (shrink)
Discussing the relationship of mathematics to chemistry is closely related to the emergence of physical chemistry and of quantumchemistry. We argue that, perhaps, the most significant issue that the 'mathematization of chemistry' has historically raised is not so much methodological, as it is philosophical: the discussion over the ontological status of theoretical entities which were introduced in the process. A systematic study of such an approach to the mathematization of chemistry may, perhaps, contribute (...) to the realist/antirealist debate. To this end, in this paper we briefly discuss Lewis' introduction of fugacity and activity to his chemical thermodynamics and more fully analyze the issues surrounding the appropriation of resonance by Linus Pauling into quantumchemistry, particularly as these issues arose in organic chemistry as discussed by George W. Wheland. (shrink)
After Heitler and London published their pioneering work on the application of quantum mechanics to chemistry in 1927, it became an almost unquestioned dogma that chemistry would soon disappear as a discipline of its own rights. Reductionism felt victorious in the hope of analytically describing the chemical bond and the structure of molecules. The old quantum theory has already produced a widely applied model for the structure of atoms and the explanation of the periodic system. This (...) paper will show two examples of the entry of quantum physics into more classical fields of chemistry: inorganic chemistry and physical chemistry. Due to their professional networking, George Hevesy and Michael Polanyi found their ways to Niels Bohr and Fritz London, respectively, to cooperate in solving together some problems of classical chemistry. Their works on rare earth elements and adsorption theory throws light to the application of quantum physics outside the reductionist areas. They support the heuristic and persuasive value of quantum thinking in the 1920–1930s. Looking at Polanyi’s later oeuvre, his experience with adsorption theory could be a starting point of his non-justificationist philosophy. (shrink)
In line with their previous studies dedicated to quantumchemistry (Gavroglu and Simões 1994, 2000; Simões and Gavroglu 1997, 2001), the last joint publication by Kostas Gavroglu and Ana Simões provides the readers not only with a fine-grained, rigorous, and highly valuable book on the history of science but also with stimulating epistemological insights about the way ‘in-between’ disciplines, to use the authors’ turn of phrase, emerge from the convergence of diverging ‘styles’ of research and heterogeneous practices. To (...) make their point, the authors divide their work into four main chapters before drawing epistemological and historiographical conclusions in the fifth and last part of their work. The first chapter entitled ‘QuantumChemistry qua Physics: The Promises and Deadlocks of Using First Principles’ focuses mainly on German researchers’ contributions in the development of quantumchemistry. In this respect, it highlights four pioneering moments: (1) Walter Heitler and Fritz Lo. (shrink)
In this paper we will discuss some of the issues related to the attempts of Ralph Howard Fowler and Nevil Vincent Sidgwick to create a legitimizing space for quantum and theoretical chemistry in Britain. Although neither Fowler nor Sidgwick made original contributions to quantumchemistry, they followed closely the developments in the discipline, participated in meetings and discussions and delivered lectures, talks and addresses, where methodological topics, ontological questions and implicitly the problem of autonomy of the (...) new discipline vis-à-vis both physics and chemistry were taken to be pressing issues. In particular, they encouraged young people to work within the nascent discipline. Viewing quantumchemistry as a branch of applied mathematics became an emblematic characteristic of the practice of the new discipline in Great Britain. (shrink)
In Neither Physics Nor Chemistry, Kostas Gavroglu and Ana Simoes examine the evolution of quantumchemistry into an autonomous discipline, tracing its development from the publication of early papers in the 1920s to the dramatic changes ...
This paper discusses how computational modeling combines the autonomy of models with the automation of computational procedures. In particular, the case of ab-initio methods in quantumchemistry will be investigated to draw two lessons from the analysis of computational modeling. The first belongs to general philosophy of science: Computational modeling faces a trade-off and enlarges predictive force at the cost of explanatory force. The other lesson is about the philosophy of chemistry: The methodology of computational modeling puts (...) into doubt claims about the reduction of chemistry to physics. (shrink)
This note is intended to address one particular issue in the relative status of QuantumChemistry in comparison to both Chemistry and Physics. It has been suggested, in the context of the question of the reduction relations between Chemistry and Physics that QuantumChemistry as a research programme is incapable of furnishing useful guidance to practising chemists. If true, this claim will let us qualify QuantumChemistry as a degenerating research programme, which, (...) due to its complexity has difficulty to be applied to Chemistry. This claim is shown to be false. The replacement claim I wish to make is that QuantumChemistry is perfectly capable of furnishing such guidance, but renders the ontological status of many models favored by chemists problematic. QuantumChemistry, however, validates these models in an instrumental fashion. I will argue that QuantumChemistry is a progressive research programme. (shrink)
In this essay I consider whether the theory of organic chemistry is reducible to the theory of quantumchemistry. Using philosophical machinery developed by James Woodward, I characterize the understanding provided by both theories. Then I argue that there are systematic reasons to suspect that quantumchemistry is incapable of supporting some of the significant explanations, predictions, and applications underwritten by an understanding of theoretical organic chemistry. Consequently, even should quantumchemistry be (...) ‘reducible to’ quantum physics in some suitable sense, there are good reasons to doubt that many of the significant results of organic chemistry could be reproduced by quantumchemistry alone. (shrink)
Mulliken proposed an Aufbauprinzip for the molecules on the basis of molecular spectroscopy while establishing, point by point, his concept of molecular orbit. It is the concept of electronic state which becomes the lever for his attribution of electronic configurations to a molecule. In 1932, the concept of orbit was transmuted into that of the molecular orbital to integrate the probabilistic approach of Born and to achieve quantitative accuracy. On the basis of the quantum works of Hund, Wigner, Lennard-Jones (...) and group theory, he suggested the fragment method to establish the characteristics of molecular orbital for polyatomic molecules. These developments make it possible to bring elements of thought on the relation between a molecular whole and its parts . An operational realism combined with the second law of thermodynamics can pave the way for interesting tracks in the mereological study of chemical systems. (shrink)
This paper analyses Richard Bader’s ‘operational’ view of quantum mechanics and the role it plays in the the explanation of chemistry. I argue that QTAIM can partially be reconstructed as an ‘austere’ form of quantum mechanics, which is in turn committed to an eliminative concept of reduction that stems from Kemeny and Oppenheim. As a reductive theory in this sense, the theory fails. I conclude that QTAIM has both a regulatory and constructive function in the theories of (...)chemistry. (shrink)
Differing views on reduction are briefly reviewed and a suggestion is made for a working definition of 'approximate reduction'. Ab initio studies in quantumchemistry are then considered, including the issues of convergence and error bounds. This includes an examination of the classic studies on CH2 and the recent work on the Si2C molecule. I conclude that chemistry has not even been approximately reduced.
Harold Kincaid in Individualism and the Unity of Science postulates a model of unity-without-reduction in order to accurately describe the relation between individualism and macroeconomics. I present this model and apply it to the description of the relation between chemistry and quantum mechanics. I argue that, when it comes to the description of molecular structure, chemistry and quantum mechanics are unified in Kincaid’s sense. Specifically, the two disciplines contribute to the formation of a unified body of (...) knowledge with respect to molecular structure. (shrink)
Most contemporary chemists consider quantum mechanics to be the foundational theory of their discipline, although few of the calculations that a strict reduction would seem to require have ever been produced. In this essay I discuss contemporary algebraic and diagrammatic representations of molecular systems derived from quantum mechanical models, specifically configuration interaction wavefunctions for ab initio calculations and molecular orbital energy diagrams. My aim is to suggest that recent dissatisfaction with reductive accounts of chemical theory may stem from (...) both the inability of standard accounts of reduction to incorporate the diverse forms of representation found in chemical practice and our philosophical predilection to analyze all connections between theories in terms of logical reduction. (shrink)
The chemical nature of element 72, subsequently named hafnium, is generally regarded as a prediction from Bohr's theory of the periodic system and hence as a prediction from quantum theory. It is argued that both of these views and in particular the latter are mistaken. The claim in favour of Bohr's theory is weakened by his accommodation of independent chemical arguments and the claim in favour of quantum theory is untenable since the prediction is not strictly deductive.
In this paper, we outline the foundations of the time invariant, non-unitary covering of quantumchemistry known as hadronic chemistry, we illustrate its validity by reviewing the exact representations of the binding energies of the Hydrogen and water molecules, and present new advances.
The author looks at the continuing debate about the meaning of quantum theory. The historical development of the theory is traced from the turn of the century through to the 1930's, and the famous debate between Niels Bohr and Albert Einstein.
In his classic work The Mind and its Place in Nature published in 1925 at the height of the development of quantum mechanics but several years after the chemists Lewis and Langmuir had already laid the foundations of the modern theory of valence with the introduction of the covalent bond, the analytic philosopher C. D. Broad argued for the emancipation of chemistry from the crass physicalism that led physicists then and later—with support from a rabblement of philosophers who (...) knew as much about chemistry as etymologists—to believe that chemistry reduced to physics. Here Broad’s thesis is recast in terms more familiar to chemists. In the hard sell of particle physics, several prominent figures in chemistry—Hoffmann, Primas, and Pauling—have had their views interpreted to imply that they were sympathetic to greedy reductionism when in fact they were not. Indeed, being chemists without physicists as alter egos, they could not but side with Broad’s contention that chemistry, as a science that deals primarily in emergent phenomena which are beyond the purview of physicalism, owes no acquiescence to particle physics and its ethereal wares. Historically, among the most widely used expediencies in chemistry and materials science are additivity or mixture rules and their cohort transferability, all of which are devised and used under the mantle of naive reductionism. Here it is argued that while the transfer of functional groups between molecules works empirically to an extent, it is strictly outlawed by the no-cloning theorem of quantum mechanics. Several illustrative examples related to chemistry’s irreducibility to physics are presented and discussed. The failure of naive reductionism exhibited by the deep-inelastic scattering of leptons by A > 2 nuclei is traced to the same flawed reasoning that was the original basis of Moffitt’s ‘atoms in molecules’ hypothesis, the neglect of context, nuclei in the case of high-energy physics and molecules in the case of chemistry. A non-exhaustive list of other contexts from physics, chemistry, and molecular biology evidencing similar departures from the ideal of additivity or reductionism is provided for the perusal of philosophers. Had the call by the mathematician J. T. Schwartz for developments in mathematical linguistics possessed of a less single, less literal, and less simple-minded nature been met, perhaps it might have persuaded scientists to abandon their regressive fixation with unphysical reductionism and to adapt to new methodologies that engender a more nuanced handling of ubiquitous emergent phenomena as they arise in Nature than is the case today. (shrink)
The many-faced relationship between chemistry and physics is one of the most discussed topics in the philosophy of chemistry. In his recent book Reducing Chemistry to Physics. Limits, Models, Consequences, Hinne Hettema conceives this relationship as a reduction link, and devotes his work to defend this position on the basis of a “naturalized” concept of reduction. In the present paper I critically review three kinds of issues stemming from Hettema’s argumentation: philosophical, scientific and methodological.
Chemistry and physics are two sciences that are hard to connect. Yet there is significant overlap in their aims, methods, and theoretical approaches. In this book, the reduction of chemistry to physics is defended from the viewpoint of a naturalised Nagelian reduction, which is based on a close reading of Nagel's original text. This naturalised notion of reduction is capable of characterising the inter-theory relationships between theories of chemistry and theories of physics. The reconsideration of reduction also (...) leads to a new characterisation of chemical theories. This book is primarily aimed at philosophers of chemistry and chemists with an interest in philosophy, but is also of interest to the general philosopher of science. (shrink)
The concepts of atoms and bonds in molecules which appeared in chemistry during the nineteenth century are unavoidable to explain the structure and the reactivity of the matter at a chemical level of understanding. Although they can be criticized from a strict reductionist point of view, because neither atoms nor bonds are observable in the sense of quantum mechanics, the topological and statistical interpretative approaches of quantumchemistry (quantum theory of atoms in molecules, electron localization (...) function and maximum probability domain) provide consistent definitions which accommodate chemistry and quantum mechanics. (shrink)
This paper widens the scope of our previous paper (Harré and Llored in Found Chem 13:63–76, 2011) by scrutinizing how whole/parts relations are involved in the study of molecules. In doing so, we point out two mereological fallacies which endanger both philosophical and chemical inferences. We also further explore how the concept of affordance is related to our mereological investigation. We then refer to quantumchemistry in order to pave the way for a new mereological approach for (...) class='Hi'>chemistry. (shrink)
Intra-molecular connectivity (that is, chemical structure) does not emerge from computations based on fundamental quantum-mechanical principles. In order to compute molecular electronic energies (of C 3 H 4 hydrocarbons, for instance) quantum chemists must insert intra-molecular connectivity “by hand.” Some take this as an indication that chemistry cannot be reduced to physics: others consider it as evidence that quantumchemistry needs new logical foundations. Such discussions are generally synchronic rather than diachronic —that is, they neglect (...) ‘historical’ aspects. However, systems of interest to chemists generally are metastable . In many cases chemical systems of a given elemental composition may exist in any one of several different metastable states depending on the history of the system. Molecular structure generally depends on contingent historical circumstances of synthesis and separation, rather than solely or mainly on relative energies of alternative stable states, those energies in turn determined by relationships among components. Chemical structure is usually ‘kinetically-determined’ rather than ‘thermodynamically-determined.’ For instance, cyclical hydrocarbon ring-systems (as in cyclopropene) are produced only in special circumstances. Adequate theoretical treatments must take account of the persistent effects of such contingent historical events whenever they are relevant—as they generally are in chemistry. (shrink)
This paper combines naturalized metaphysics and a philosophical reflection on a recently evolving interdisciplinary branch of quantumchemistry, ab initio molecular dynamics. Bridging the gaps among chemistry, physics, and computer science, this cutting-edge research field explores the structure and dynamics of complex molecular many-body systems through computer simulations. These simulations are allegedly crafted solely by the laws of fundamental physics, and are explicitly designed to capture nature as closely as possible. The models and algorithms employed, however, involve (...) many approximations and significant degrees of idealization of their target systems. Therefore, for philosophers of science the pivotal question of whether relying only on the fundamental laws of physics supports a reductionist or realist stance arises. One conceivable answer to this question is that the irreducible approximations and idealizations support rather anti-realist positions. After reviewing an influential attitude in the philosophy of computer simulations and the debate concerning scientific realism, I offer a fair interpretation of such ab initio modelling in quantumchemistry within a naturalistic metaphysical framework that gives rise to a specific type of ontic structural realism. (shrink)
I claim that the question of whether chemistry is reduced to quantum mechanics is more ambiguous and multi-faceted than generally supposed. For example, chemistry appears to be both reduced and not reduced at the same time depending on the perspective that one adopts. Similarly, I argue that some conceptual issues in quantum mechanics are ambiguous and can only be laid to rest by embracing paradox and ambiguity rather than regarding them as obstacles to be overcome. Recent (...) work in the reduction of chemistry is also reviewed, including discussions of the ontological reduction of chemistry and the question of the emergence of chemistry from physics. (shrink)
In this essay, we argue that there exist obvious parallels between questions that inform philosophy of chemistry and the so-called hard problem of consciousness in philosophy of mind. These include questions regarding the emergence of higher-level phenomena from lower-level physical states, the reduction of higher-level phenomena to lower-level physical states, and 'downward causation'. We, therefore, propose that the 'hard problem' of consciousness should be approached in a manner similar to that used to address parallel problems in philosophy of (...) class='Hi'>chemistry. Thus, our contribution begins by scrutinizing the ways chemists and quantum chemists think about and use different levels of organization and chemical relations and relata and then investigates the problem of 'downward causation' as it relates to the question of emergence. We demonstrate that the science of the transformation of 'substances', namely chemistry, enables us to go beyond substantialism and to develop, instead, a non-substantialist account of levels of reality. Similarly, the 'hard problem' of consciousness will require that we transcend traditional emergentism and its substantialist conception of mind. As with chemical phenomena, mental phenomena must be examined in terms of the relationality of wholes and parts, and this will require the development of a mereology that explains how parts and wholes may co-define each other. Like the non-classical and non-transitive mereology that has been proposed for quantumchemistry, an extended mereology for philosophy of mind must be one that entangles the whole, its parts, and the environment, thus rendering 'downward causation' into a relational concept. This proposal is neither a reductionist analysis that only needs the parts to define the whole, nor a merely holistic description within which the whole is necessary to define the parts. Rather, we propose that the parts, the whole, and the environment co-define each other so that our understanding of parts, wholes, and environment as independent concepts must itself be altered. (shrink)
Periodic tables (PTs) are the ‘ultimate paper tools’ of general and inorganic chemistry. There are three fields of open questions concerning the relation between PTs and physics: (i) the relation between the chemical facts and the concept of a periodic system (PS) of chemical elements (CEs) as represented by PTs; (ii) the internal structure of the PS; (iii)␣The relation between the PS and atomistic quantumchemistry. The main open questions refer to (i). The fuzziness of the concepts (...) of chemical properties and of chemical similarities of the CE and their compounds guarantees the autonomy of chemistry. We distinguish between CEs, Elemental Stuffs and Elemental Atoms. We comment on the basic properties of the basic elements. Concerning (ii), two sharp physical numbers (nuclear charge and number of valence electrons) and two coarse fuzzy ranges (ranges of energies and of spatial extensions of the atomic orbitals, AOs) characterize the atoms of the CEs and determine the two-dimensional structure of the PS. Concerning (iii), some relevant ‘facts’ about and from quantumchemistry are reviewed and compared with common ‘textbook facts’. What counts in chemistry is the whole set of nondiffuse orbitals in low-energy average configurations of chemically bonded atoms. Decisive for the periodicity are the energy gaps between the core and valence shells. Diffuse Rydberg orbitals and minute spin–orbit splittings are important in spectroscopy and for philosophers, but less so in chemical science and for the PS. (shrink)
According to ontological reductionism, molecular chemistry refers, at last, to the quantum ontology; therefore, the ontological commitments of chemistry turn out to be finally grounded on quantum mechanics. The main problem of this position is that nobody really knows what quantum ontology is. The purpose of this work is to argue that the confidence in the existence of the physical entities described by quantum mechanics does not take into account the interpretative problems of the (...) theory: in the discussions about the relationship between chemistry and physics, difficulties are seen only on the side of chemistry, whereas matters highly controversial on the side of physics are taken for granted. For instance, it is usually supposed that the infinite mass limit in the Born-Oppenheimer approximation leads by itself to the concept of molecular framework used in molecular chemistry. We will argue that this assumption is implicitly based on an interpretative postulate for quantum mechanics, which, in turn, runs into difficulties when applied to the explanation of the simplest model of the hydrogen atom. (shrink)
A personal account is presented for the present status of mathematical chemistry, with emphasis on non-numerical applications. These use mainly graph-theoretical concepts. Most computational chemical applications involve quantumchemistry and are therefore largely reducible to physics, while discrete mathematical applications often do not. A survey is provided for opinions and definitions of mathematical chemistry, and then for journals, books and book series, as well as symposia of mathematical chemistry.
In this paper we will address the problem of the existence of orbitals by analyzing the relationship between molecular chemistry and quantum mechanics. In particular, we will consider the concept of orbital in the light of the arguments that deny its referring character. On this basis, we will conclude that the claim that orbitals do not exist relies on a metaphysical reductionism which, if consistently sustained, would lead to consequences clashing with the effective practice of science in its (...) different branches. (shrink)
Some recent work in mathematical chemistry is discussed. It is claimed that quantum mechanics does not provide a conclusive means of classifying certain elements like hydrogen and helium into their appropriate groups. An alternative approach using atomic number triads is proposed and the validity of this approach is defended in the light of some predictions made via an information theoretic approach that suggests a connection between nuclear structure and electronic structure of atoms.