Dyson notation

Dyson notation org chem A notation system for representing organic chemicals developed byG. Malcolm Dyson the compound is described on a single line, symbols are used for the chemical elements involved as well as for the functional groups and various ring systems for example, methyl alcohol is C.Q and phenol is B6.Q. dT-son no.ta-shon ... 

G.M. Dyson, M.F. Lynch and H.L, Morgan, "A Modified lUPAC-Dyson Notation System for Chemical Structures, Inform. Storage Retr. 4 (1968), 27-83. 

SMILES notation (Simplified Molecular Input Line Entry System) used in the Pomona College MedChem project ( ) the Dyson notation (5) adopted as a standard by the International Union for Pure and Applied Chemistry (lUPAC) and Wiswesser Line Notation (WLN), which became the actual standard used in the chemical industry (6). The rules of WLN were standardized by the Chemical Notation Association (CNA), but the two major WLN data bases. Index Chemicus Registry System, ICRS, from the Institute for Scientific Information and the Commercially Available Organic Chemicals Index, CAOCI (7) used somewhat different conventions. 

Substructure searching based on linear notations can be accomplished in both an automated and non-automated mode. Dyson... 

Here, P is the Dyson time-ordering operator [57], Q (t)IP is the coordinate in the interaction picture with respect to the thermal bath and to the diagonal part of the Hamiltonian of the H-bond bridge, and the notation (( )e)siow has the meaning of a partial trace on the thermal bath and on the H-bond bridge coordinates. 

G.M. Dyson, A New Notation and Enumeration System for Organic Compounds Longmans, Green and Co., London, 2-nd Ed., 1949. 

None of these, however, can take the place of a system of good names which can be used in writing and speaking and in subject indexes. There is, however, no reason why a system of notation, such as that of Dyson (5) should not be used to engender a system of fiducial nomenclature. 

Using our matrix notation, we can recast Eqs. (33) and (41) in the form of Dyson equations... 

However, we do know that notations were first suggested by Dyson in October 1946 [46-48], a result of his attention having been directed in 1937 [35] to the complexity of systematically naming organic structures. His notation was adopted by lUPAC and publkhed in 1958 as a tentative international chemical notation [49] and in 1961 as an approved notation [50]. It was revised in 1968 to accommodate experience obtained from computer aq>plication of the notation [4] and revised again for the... 

G.M. Dyson, A New Notation for Organic Chemistry, Royal Institute of Chemistry Lecture, published jointly with the Chemical Sodety and the Sodety of Chemical Industry, October 1946 p. 26. 

Rules for lUPAC Notation for Organic Compounds (Longmans, 1961) is based on the Dyson system and provides a linear cipher for all chemical substances of known structure which can be adopted for indexes. It supersedes A Proposed International Chemical Notation (1958). Some useful lists of symbols have also been published e.g. the Manual of Physico-chemical Symbols and Terminology (issued separately and in J. Amer. chem. Soc. 82, 5517-22 (1960), and the now out-of-date Symbols of Thermodynamical and Physico-chemical Quantities and Conventions Relating to their Use Chem. Ind. 15, 860-5 (1937) Analyst 62, 800-5 (1937)), and International Physico-chemical Symbols (Z. Elektrochem. 27, 5TI-yi (1921). Another volume in the Advances in Chemistry series. No. 14, Nomenclature for Terpene Hydrocarbons, describes the system approved by the ACS and accepted in part by lUPAC. 

Let us now consider elastic scattering of a particle from a system. It has been often emphasized that one can avoid the computation of complicated many-particle scattering states by introducing an optical wave function. This function obeys a single-particle Schrodinger equation, the potential of which is called optical potential. The optical potential and wave function are not unique. A particularly convenient choice is to relate them to the one-particle GF. Bell and Squires were the first to show that the optical potential may be identified with the self-energy of this GF. The self-energy i7(a>) connects the GF with the free GF via the Dyson equation. In matrix notation this renowned equation reads... 

Various line notations have been devised to depict accurately both the atomic content and the orientation of the compound. Much of the focus in creating notation systems has been geared toward computer input and manipulation of structures. Some of the well-known notations include Wiswes.ser (WLN), Dyson-IUPAC, Hayward, Skolnik, Gremas and more recently also SMILES, and ROSDAL. All of these systems require a detailed memorization of their rules and conventions and are limited strictly to the audience familiar with those rules. 

WLN was one of the principal contenders for international acceptance by lUPAC, and because it was already being used by many chemical companies in the USA it was never supplanted by other linear notations such as Dyson-IUPAC, Hayward, or Skolnik. The general concept of all these notations does not differ from that in WLN, the differences lie only in details of the adopted encoding schemes. 

G. n.Dyson, "A New Notation and Enumeration System for Organic Compounds". 2nd Ed., London Longmans 1949 "Rules for I.U.P.A.C. Notation for Organic Compounds". London Longmans 1961... 

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