Coulson, Charles

Coulson, Charles A. "Theoretical Chemistry Past and Future. Lecture delivered before The University of Oxford,... 

Coulson Charles A. 328, 691 Cowan Clyde L. 511 Crafts James Mason 703 Cram Donald James 745 Crego Calama Mercedes 856 Cremer Dieter 388 Crepeau Claude 3, 47 Crick Francis 285 Csaszar Attila G. 139 Csizmadia Imre G. 406 Curie-Sklodowska Marie 765, 805 Curtiss Charles F. 760... 

Coulson, Charles Alfred (1910-74) British theoretical chemist. Coulson was very influential in promoting the use of quantum mechanics in chemistry, particularly the use of molecular orbital theory. He used this theory to describe conjugated systems such as benzene and to justify the concept of partial valence. Coulson was also able to use molecular orbital theory to predict the properties of many organic... 

Robert S. Mulliken John Clarke Slater Charles Coulson... 

Chemistry used to be less "deep," less "fundamental" than physics, said Charles Coulson in his inaugural lecture of an Oxford chair in theoretical chemistry in 1973, but "this is no longer the case." C. A. Coulson, "Theoretical Chemistry Past and Future," lecture delivered before the University of Oxford on February 23, 1973, ed. S. L. Altman (Oxford Clarendon, 1974) 69. 

In his inaugural lecture for the chair of theoretical chemistry at Oxford in 1973, Charles Coulson recalled a student asking him, "Why are you not located in physical chemistry " Nemst and other physical chemists at the turn of the century had thought of physical chemistry as theoretical chemistry. In contrast, by 1970, as Coulson put it, "the theoretical chemist is concerned not just with physical chemistry but with all branches of chemistry." 1... 

Charles Coulson, "Recent Developments in Valence Theory," page proofs, delivered at Australian symposium on "Fifty Years of Valence Theory," 2, Coulson Papers, B.41.10, Bod.Oxford. 

Charles Coulson, 4, "A History of Quantum Theory and Applications in Chemistry," 12-page typescript of after-dinner speech given August 16, 1971, at the Fourth Canadian Symposium on Theoretical Chemistry,... 

Charles Coulson, "What Is a Chemical Bond " lecture at Basler Chemische Gesellschaft, April 26, 1951, 25-page typescript, 36, Coulson Papers, Bod.Oxford. 

In 1930, the student Charles Coulson wrote out as the first lines of his chemistry exercise book at Clifton College in Bristol, "Physics is Chemistry. Chemistry is Physics. Laws of Conservation of energy and matter are FUND AMENT AL LAWS. Lavoisier was the first to realize this clearly." 1 Almost sixty years later, the editors of the Annual Review of Physical Chemistry announced that they had entertained the suggestion that "Chemical Physics" be added to the title of the journal but rejected it, even while recognizing, they said, that the difference between the practice of physical chemistry and chemical physics is "small indeed."2... 

Charles Coulson in the 1930s, when he was a student of mathematics, physics, and chemistry in Bristol and Cambridge. 

Then, in the Old Ages (1940 or 1951-1967) some ingenious people became aware that, in the case of two-body interactions, it is the two-particle reduced density matrix (2-RDM) that carries in a compact way all the relevant information about the system (energy, correlations, etc.). Early insight by Husimi (1940) and challenges by Charles Coulson were completed by a clear realization and formulation of the A-representability problem by John Coleman in 1951 (for the history, see his book [1] and Chapters 1 and 17 of the present book). Then a series of theorems on A-representability followed, by John Coleman and many... 

In a famous after-dinner address at a 1959 conference in Boulder, Colorado, Charles Coulson [1] discussed both the promises and the challenges of using the two-electron reduced density matrix (2-RDM) rather than the many-electron wavefunction as the primary variable in quantum computations of atomic and molecular systems. Integrating the A-electron density matrix,... 

In one sense, research in theoretical chemistry at Queen s University at Kingston originated outside the Department of Chemistry when A. John Coleman came in 1960 as head of the Department of Mathematics. Coleman took up Charles Coulson s challenge150 to make the use of reduced density matrices (RDM) a viable approach to the N-electron problem. RDMs had been introduced earlier by Husimi (1940), Lowdin (1955), and McWeeny (1955). The great attraction was that their use could reduce the 4N space-spin coordinates of the wavefunctions in the variational principle to only 16 such coordinates. But for the RDMs to be of value, one must first solve the celebrated N-repre-sentability problem formulated by Coleman, namely, that the RDMs employed must be derivable from an N-electron wavefunction.151 This constraint has since been a topic of much research at Queen s University, in the Departments of Chemistry and Mathematics as well as elsewhere. A number of workshops and conferences about RDMs have been held, including one in honor of John Coleman in 1985.152 Two chemists, Hans Kummer [Ph.D. Swiss Federal Technical... 

A few hardy souls may say it doesn t matter. A molecule is a collection of nuclei and electrons, with a certain charge and spin multiplicity. One might stop there and say that this defines the molecule. This austere view was expressed by Charles Coulson, a pioneer of, of all things, valence ...a bond does not really exist at all it is a most convenient fiction... [4], However, the bond concept... 

A. Simoes and K. Gavroglu, Quantum chemistry qua applied mathematics the contributions of Charles Alfred Coulson (1910-1974) , Hist. Stud. Phys. Biol. Sci., 1999, 29, 363 106. 

Some years later, Charles A. Coulson argued that the splendid and elegant elucidation of so large a part of chemistry by quantum mechanics forbade chemists to be happy with an electronic theory of valence couched in pre-quantum mechanical terms. In 1952, he was careful to stress in his book Valence that quantum chemistry should be understandable by a chemist with no mathematical training. 

Charles A. Coulson and Andrew Streitwieser, Dictionary of n-Electron Calculations, Pergamon, New York, 1965. 

In a famous after dinner speech delivered at the Boulder Conference in 1959, the leading British Theoretical Chemist of the day, Professor Charles A. Coulson, predicted that... 

In 1955, I attended the first of the Summer Schools in Theoretical Chemistry, organised by Charles Coulson, then Rouse-Ball Professor of Mathematical Physics at Oxford, to introduce young chemists to the Molecular Orbital (MO) Theory, to which he made outstanding contributions. The MO theory gave me a wider perspective for the interpretation of molecular spectra and the study of molecular structures and reaction mechanisms. 

I was impressed and inspired by Charles Coulson (1910-74), the evangelical teacher of quantum chemistry. Quantum mechanics was not taught to chemistry students when I was an undergraduate, and Coulson s Summer Schools introduced some 35 to 60 chemistry graduate students, postdoctoral fellows and university lecturers to the subject each year from 1955 to 1973. His lectures were crystal clear, and his communication went beyond the power of his words, for one had to work hard at the problems he set, as part of the course, to really understand what he had said. 

It is also possible to be surprised in retrospect. In the days when requests for reprints measured the interest in a published paper Charles Coulson told me that he was many a time perplexed to find that papers he had tossed off in an afternoon proved to be so popular that he quickly exhausted his reprint supply. Others with results that had been hard to get and that he thought important seemed to pass by unnoticed and wither on the vine. It is a common experience. Paper [49] with... 

After comparing experimental and calculated dipole moments, Charles A. Coulson suggested that the Cl atom in HCl is sp hybridized, (a) Give the orbital electronic structure for an sp hybridized Cl atom, (b) Which HCl molecule would have a larger dipole moment—one in which the chlorine uses pure p orbitals for bonding with the H atom or one in which sp hybrid orbitals are used ... 

Charles Coulson, a student of Lennard-Jones, is largely responsible for the development and the widespread appreciation of molecular-orbital theory. He, his students, and the visitors to his research group explored many facets of this subject, and unified many new ideas over the years. In his roles as innovator, leader in this field, and finally statesman of these parts of chemistry, chemical physics and applied mathematics, he provided a truly creative atmosphere for his research group. For many years there was no comparable place for the study of molecular theory of complex molecules, and for that reason the very wide interest that now exists in molecular-orbital theory can be attributed to Coulson s imagination and teaching. 

Charles A. Coulson, born Worcestershire, England, 1910. Ph.D. Cambridge, 1935. lYofessor of theoretical physics. King s College, London professor of mathematics, Oxford professor of theoretical chemistry, Oxford. Died Oxford, 1974. Best known for his book Valence (the 1st Fid., 1952). 

Most work on the integral Eq. (3) has utilized an iterative method of Svartholm [4,5] for solving it. The integral equation was first applied to He and hJ by Roy McWeeny and Charles Coulson [6,7] during McWeeny s doctoral work. At the 5th Canadian Symposium on Theoretical Chemistry, Ottawa, 1974, McWeeny delivered a tribute to Coulson who had passed away in January of that year. In that lecture, McWeeny described how he felt when he was first assigned the project by Coulson ... 

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