Biographical Memoirs Volume 74 (1998) / Chapter Skim
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David Harker
David Harker
Pages 126-143
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To this clay, the Harker section en c! the Harker construction play essential roles in the determination of the structures of very large molecules.
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(1930-33) After graduation from Berkeley, Dave continued on as a graduate student, but in 1930 he left to take a job as laboratory technician at the research laboratory of the Atmospheric Nitrogen Corp.
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This function relates the experimentally observable X-ray diffraction intensities with the totality of interatomic vectors in the crystal. Owing to the large number of interatomic vectors, interpreting the Patterson function was, en c!
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the test of time en c! even tociay is inclispensable for the determination of macromolecular structures, particularly in those cases where the structure contains a small number of heavy atoms, when Patterson techniques are useful.
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Harker cliscoverec! that the orcler of decreasing prominence of the faces of a crystal was the same as the order of decreasing interplanar lattice spacings, including the halvings, thirdings, and quarterings due to the space group symmetries.
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It was during Dave's tenure at General Electric that he and his collaborator John S Kasper produced their paper on the inequalities among the crystal structure factors, the famous Harker-Kasper inequalities.
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" Then we went madly to work, and in a couple of weeks we had enough algebraic apparatus assembled "unitary" structure factors, sum and difference inequalities, etc. to be useful.
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I was unhappy, however, that the treatment so far was only for the case of one kind of atom. Dave said that could be fixed, and in short order he proposed using the unitary atomic structure factor, f.
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I was working closely with both John and Dave on the decaborane problem at the time and clearly recall the sequence of events as John has described. I was also working in the office while John was busy working with the relationship of Schwartz's inequality and the structure factors to possibly help determine signs when Dave arrived in the office and became very excited at the possibilities of its use.
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After months of interminable negotiations, the decision finally was made to establish the Protein Structure Project at the Polytechnic Institute of Brooklyn in July 1950. There Dave en c!
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the whole project to the Roswell Park Cancer Institute (then known as the Roswell Park Memorial Institute) , where he acceptec!
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from the Roswell Park Cancer Institute, but he continues! his crystallographic studies as a research scientist emeritus at the Hauptman-Woodward Institute (then known as the Medical Foundation of Buffalo)
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for his determination of the molecular structures of biologically important substances. On Dave's eighty-second birthday, in 198S, the David Harker Endowment Func!
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WISH TO MAW grateful acknowledgement to Ms. Tava Shanchuk for her help in writing an initial draft of this biography; this was of considerable assistance to me in the preparation of the final manuscript.
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Phases of Fourier coefficients directly from crystal diffraction data. Acta Crystallogr.
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Crystalline forms of bovine pancreatic ribonuclease: techniques of preparation, unit cells, and space groups. Acta Crystallogr.
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A 37:286-92. 1991 Two-dimensionally infinite polyhedra with vertices related by symmetry operations.
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