Klaus Ruedenberg

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Klaus Ruedenberg , originally Klaus Rüdenberg , (born August 25, 1920 in Bielefeld ) is a German-born American chemist ( theoretical chemistry , quantum chemistry ).

Life

Klaus Ruedenberg was the only son of the Jewish weaving entrepreneur Otto Rüdenberg and his wife Meta Sophie, née Wertheimer. He graduated from high school in Bielefeld as one of the last two Jewish students who were allowed to graduate. In 1938 he emigrated to Switzerland, where he initially studied at an English-language college preparatory school ( Institut Montana 1939). His parents visited him there, but returned to Germany without heeding a warning from a Swiss friend. During the November pogroms in 1938 that was synagogue Bielefelddesecrated and burned down. Rüdenberg's mother died on July 20, 1942 in a Bielefeld hospital after a long illness. His father was a few days later on 31 July 1942 by Bielefeld in the Theresienstadt concentration camp deported and later in the concentration camp Auschwitz murdered.

Ruedenberg studied chemistry and mathematics at the University of Friborg with a diploma in 1944 and received his doctorate in theoretical physics from the ETH Zurich in 1950 with Gregor Wentzel . From 1950 to 1955 he conducted research with Robert Mulliken at the University of Chicago . In 1955 he received US citizenship and became an assistant professor and later an associate professor at Iowa State University (then Iowa State College) and was at the Ames Laboratory of the Atomic Energy Commission (later the DOE). From 1962 to 1964 he was Professor of Chemistry at Johns Hopkins University and then, until his retirement in 1991, Senior Scientist at the Ames Laboratory at Iowa State University. He was also Distinguished Professor of Sciences and Humanities there from 1978.

While his first published work concerned the meson theory of nuclear forces, he turned to the quantum theory of molecular structure at Mulliken in Chicago. At that time the aim was to carry out ab initio calculations of diatomic molecules with self-consistent wave functions, with Mulliken's doctoral student Clemens CJ Roothaan achieving a breakthrough. An important step was the evaluation of the integrals for the repulsion energies of the electrons with exponential atomic wave functions. For this purpose, Ruedenberg developed a practicable method with which Charles W. Scherr carried out the first (and due to the early advent of computers only) ab initio calculation of a molecule (the nitrogen molecule in its ground state) “by hand” in 1954, that is, with desktop computers (the accuracy of which was later confirmed with computers). Soon afterwards, Ruedenberg and Scherr developed a “free electron network model” of aromatic hydrocarbons, inspired by John R. Platt . They proved its equivalence with the conventional LCAO method , so that their model could serve as an illustration of the LCAO method. Ruedenberg then expanded this with Norbert Ham to include electron interactions and worked with Hummel to calculate the electronic structure of various polycycles using an augmented tight binding method .

He then turned to the nature of delocalization in aromatics, for which there were two different explanations at the time, namely as an effect of potential energy (at that time the predominant approach) or as an effect of kinetic energy (in the network model of free electrons). Ruedenberg found that despite the interplay between the two effects, in the end the change in the term of the kinetic energy was decisive for the binding in the delocalization. He investigated this question from different perspectives in the 1960s and 1970s, which was also reflected in the book by Robert Mulliken on the calculation of diatomic molecules and in a much-cited review article by Ruedenberg in the Reviews of Modern Physics . With Edmiston, Ruedenberg also developed a theory of localized molecular orbitals from 1963. Later he dealt among other things with the areas of potential energy of molecules and electron correlations in molecules.

Ruedenberg holds honorary doctorates from the Universities of Basel (1975), Bielefeld (1991) and Siegen (1994). In 2018 he received the Schrödinger Medal , in 2002 the American Chemical Society Award in Theoretical Chemistry and in 1982 the American Chemical Society Midwest Award. He is a fellow of the American Association for the Advancement of Sciences , the American Physical Society, and the American Institute of Chemists , is a member of the International Academy of Quantum Molecular Science, and an honorary member of the International Academy of Mathematical Chemistry. In 1966/67 he was a Guggenheim Fellow and in 1982 a Fulbright Scholar (and with the Fulbright Scholarship in Australia at Monash University and at the Chemical Physics Lab of CSIRO in Melbourne). 1966/67 he was visiting professor at the ETH Zurich, 1973 at the University of California, Santa Cruz, 1974 at the University of Bonn, 1970 at the Washington State University and 1987 at the University of Kaiserslautern.

He was editor of Theoretica Chimica Acta from 1985 to 1997 .

In 1948 he married the Swiss Veronika Kutter (died 2004), with whom he has three daughters and a son.

Fonts (selection)

  • with CW Scherr: Free-Electron Network Model for Conjugated Systems. I. Theory, J. Chem. Phys., Vol. 21, 1953, pp. 1565-1581
  • Free-Electron Network Model for Conjugated Systems. V. Theoretical Equivalence with the LCAO MO Model, J. Chem. Phys., Vol. 22, 1954, pp. 1878-1895 (1954).
  • with CCJ Roothaan, W. Jaunzemis: A Study of the Two-Center Hybrid Integrals and a Unified Treatment of the Hybrid, Coulomb, and One-Electron Integrals, J. Chem. Phys., Volume 24, 1956, pp. 201-220 .
  • with NS Ham: Electronic Interaction in the Free-Electron Network Model for Conjugated Systems. I. Theory, J. Chem. Phys., Vol. 25, 1956, pp. 1-13
  • with NS Ham: Mobile Bond Orders in Conjugated Systems, J. Chem. Phys., Volume 29, 1958, pp. 1215-1222
  • Quantum Mechanics of Mobile Electrons in Conjugated Bond Systems, Part 1-6 (Part 5 with EM Layton), J. Chem. Phys., Volume 34, 1961, pp. 1861, 1878, 1884, 1892, 1897, 1907
  • with R. Hummel: Electronic Structure and Spectra of Conjugated Hydrocarbons, J. Phys. Chem., Vol. 66, 1962, pp. 2334-2359
  • with C. Edmiston: Chemical Binding in the Water Molecule, J. Phys. Chem., Vol. 68, 1964, pp. 1628-1653
  • with EM Layton Jr .: Chemical Binding in Diatomic Hydrides, J. Phys. Chem., Vol. 68, 1964, pp. 1654-1676
  • with JR Platt, CW Scherr, NS Ham, H. Labhart, W. Lichten: Free-Electron Theory of Conjugated Molecules, Wiley 1964 (reprints of articles)
  • The Physical Nature of the Chemical Bond, Reviews of Modern Physics, Volume 34, 1962, pp. 326-376
  • with Clyde Edmiston: Localized atomic and molecular orbitals, Reviews of Modern Physics, Volume 35, 1963, pp. 457-465, Part 2, J. Chem. Phys. Volume 43, 1965, pp. 97-115, part 3 in PO Löwdin, Quantum Theory of Atoms, Molecules and the Solid State, Academic Press 1966, pp. 263-280
  • with W. England, LS Salmon: Localized Molecular Orbitals: A Bridge between Chemical Intuition and Molecular Quantum Mechanics, Advances in Chemical Research, Volume 23, 1971, pp. 31-123
  • with W. England: Localized pi-Orbitals, Pauling Bond Orders and the Origin of Aromatic Stability, Theoretica Chimica Acta, Volume 22, 1971, pp. 196-213
  • The nature of the chemical bond. An energetic view, in: R. Daudel, Localization and Delocalization in Quantum Chemistry, Volume 1, Reidel 1975, pp. 222-245
  • with WHE Schwarz u. a .: Electron Densities, Deformation Densities, and Chemical Bonding, Angewandte Chemie, Volume 101, 1989, p. 605
  • with SS Xantheas, ST Elbert: The Potential Energy Surface of the Ground State of Carbon Dioxide, Chem. Phys. Letters, vol 166, 1990, pp 39-42.
  • with G. Atchity: A Local Understanding of the Quantum Chemical Geometric Phase Theorem for Potential Energy Surface Intersections, J. Chem. Phys., Volume 110, 1999, pp. 4208-4212
  • with MW Schmidt: Physical Understanding through Variational Reasoning: Electron Sharing and Covalent Bonding, J. Phys. Chem., Vol. 113, 2009, pp. 1954-1968.
  • with MW Schmidt, J. Ivanic: The Physical Origin of Covalent Binding, in: G. Frenking, S. Shaik, The chemical bond. Fundamental aspects of chemical bonding, Wiley-VCH 2014

literature

  • MC Zerner, Introduction Klaus Ruedenberg, Int. J. Quant. Chem., Vol. 76, 2000, pp. 115-130
  • Curriculum Vitae of Klaus Ruedenberg. In: The Journal of Physical Chemistry A. 114, 2010, p. 8497, doi : 10.1021 / jp105602g .

Web links

Individual evidence

  1. ↑ According to American Men and Women of Science , Thomson Gale 2004, he is a US citizen
  2. ↑ Monika Minninger (ed.): From a stronghold of Reform Judaism. Collection of sources on Bielefeld Jewry in the 19th and 20th centuries . Bielefeld 2006, pp. 235-236. (Printed in excerpts: Acceptance speech by Klaus Rüdenberg for the award of an honorary doctorate at Bielefeld University on September 5, 1991)
  3. ↑ Biography of Ruedenberg, Prabook
  4. ^ Transport list XI / 1 Münster / Bielefeld / Theresienstadt in the Yad Vashem archive
  5. ^ Ruedenberg: On the Theory of Strong Coupling between Nucleons and Pseudovector Mesons. In: Helvetica Physica Acta Volume 24, 1951, pp. 89-136.
  6. ↑ The calculation required four "man-years", with two of the four executors being women.
  7. ↑ Other parts of the essay series are by John R. Platt
  8. ↑ Including a Progress Report of the Ames Laboratory from 1953 on the calculation of matrix elements of atomic orbitals
  9. ↑ A frequently cited article, which was also published in book form by MIR in Russian in 1964
personal data
SURNAME Ruedenberg, Klaus
ALTERNATIVE NAMES Rüdenberg, Klaus
BRIEF DESCRIPTION American chemist of German descent (theoretical chemistry, quantum chemistry)
DATE OF BIRTH August 25, 1920
PLACE OF BIRTH Bielefeld