Publications - Martin Buerger

Background and Early History of the American Crystallographic Association

Institute of Material Science, University of Connecticut, Storrs, Connecticut

1974 ACA Annual Meeting, College Park, PA

Reprinted from Crystallography in North America; McLachlan, D., Glusker, J.P., Eds.;
Am. Cryst. Assn., 1983, pp 153-155.

The American Crystallographic Association began life on January 1, 1950. It held its first meeting on April 10-12 of that year at Pennsylvania State College in State College, Pennsylvania. Today*, a little over a quarter of a century later the society holds its 25th meeting in the same locality, to find that the place is called University Park, the home of Pennsylvania State University.

Six years after its first meeting the origin of the ACA was outlined by William Parrish and Betty Wood in Volume IV of the Norelco Reporter. There it is recorded that the ACA is the successor of the American Society of X-Ray and Electron Diffraction and the Crystallographic Society of America. These two societies, in turn, had begun their lives as the second world war was beginning to disturb the world. Two separate groups had begun to raise the question of the usefulness of establishing a journal for crystallographic research and this eventually stimulated the formation of the Inter national Union of Crystallography which then not only took over the International Tables for X-ray Crystallography, but a short time later established Acta Crystallographica.Few of you here recall the birth of the ACA, and even fewer remember the origins and acts of the two societies which eventually merged to become the ACA. It seemed useful, then, while there are a few left who took part in the acts which led to our beginning, to briefly outline the history on this occasion.

One pre-existing branch of the ACA, the Crystallographic Society of America, had its beginning as a local organization of crystallographers in Cambridge, Massachusetts and vicinity. As I recall it, at first most of its members were a few mineralogists from the neighborhood who felt that the future of mineralogy lay in understanding the roles of crystal structures in the properties, genesis and relations between minerals. The membership included Harry Berman, Newton Buerger, Martin Buerger, William Dennen, Clifford Frondel, Cornelius Hurlbut, Joseph Lukesh as well as the chemists Cutler West, I. Fankuchen and others. According to a remark in a letter from M. J. Buerger to Paul Kerr dated May 1, 1941, this group began to meet in the winter of 1939 for the purpose of discussing their research results with each other. The meager records which remain show that I. Fankuchen addressed the second meeting, held May 1, 1941 at Harvard University, on the subject "Preparation and Handling of Small Crystals" in which, among other things, the prototype of all twiddlers was described. Volume 95 of Science, which appeared on January 2, 1942, contains a note from the secretary of the society, Clifford Frondel, to the effect that after the business meeting of November 17, 1941, held at M.I.T., Joseph Lukesh addressed the assembled crystallographers on "The Tridymite Problem." On the occasion of the fifth meeting on April 24, 1942, at M.I.T., Percy Bridgman gave an invited lecture on a crystallographic aspect of his high-pressure work, which he entitled "Polymorphism at High Pressures." After this there appears to have been a hiatus in the activities of the society due to preoccupation with war work. During this period the society lost its vice-president, Harry Berman, as a casualty of the war. When the war finally ended the society prepared for a large meeting, held at Smith College on March 21-23, 1946. On this occasion the small local society of crystallographers assumed the status of a national society. At the Smith College meeting, papers were presented by Richard S. Bear, J. D. H. Donnay, Howard Evans, I. Fankuchen, Samuel Gordon, Joseph Lukesh, Dan McLachlan, Benjamin Schaub, Newman Thibault, Edward Washken, Cutler West, and Dorothy Wrinch. The abstracts of their papers were published in the American Mineralogist, as were the abstracts of papers given at later meetings.

From the time of the earliest meetings of the Cambridge crystallographers, the possibility of launching a journal of crystallography was considered; indeed an estimate of possible subscribers was made and the financing of the undertaking discussed. Unfortunately it was found that a subsidy would be necessary to begin publication, and the society had no success in arranging for one.

The crystallographers of the American Crystallographic Society, which included biologists, ceramists, chemists, mineralogists and physicists, had banded together to present the results of their crystallographic research to one another because their own professional societies offered them little encouragement and limited discussion. In such meetings their results were overwhelmed by the routine and classical results, and their own results were little appreciated.

Meanwhile certain chemists had found some relief from this situation. Many interested in the new results coming from the study of the atomic arrangement in solid matter were members of the National Research Council's Division of Chemistry, Committee on X-Ray and Electron Diffraction, then chaired by Maurice L. Huggins. Stimulated by the efforts of the ACS to establish a journal devoted to crystallography, Huggins called a conference under the auspices of the N.R.C. Committee on X-Ray and Electron Diffraction to be held at the American Museum of Natural History in New York, June 10-11, 1941. Although no action was taken to go ahead with the journal, the attendants did agree to form a society of structure researchers. The NRC Committee on X-ray and Electron Diffraction (to which I had been appointed in 1940) took the initiative in organizing the society, and its constitution was adopted at the Gibson Island meeting of July 30, 1941. Huggins was elected its first president and Warren its first vice-president, to succeed to the presidency the next year. The second meeting was held in Cambridge, Massachusetts, December 31, 1941. Meanwhile, many names had been considered for the new society; the one finally chosen by written ballot from the many submitted was "The American Society for X-ray and Electron Diffraction," which was abbreviated ASXRED. Thus this lineage of the ACA took its name from the name of the committee which brought it into existence.

There were now two societies concerned with different aspects of crystallography. Some believed that the societies were in competition and felt it would be to the advantage of both to join forces. Others pointed out that the ASXRED was named after a tool which, though important to crystallographic testing and research, did not begin to represent the whole science of crystallography, and could, indeed, pass out of existence, as did the optical goniometer. In 1948 a joint committee of the ASXRED and the CSA was formed to consider the consolidation of the two societies. Their report was sent to both societies. The membership of the ASXRED discussed the proposal for joining on December 19, 1948 and the CSA on April 8, 1949. Both memberships voted for consolidation. The two societies merged into the American Crystallographic Association on January 1, 1950. The new society held its first meeting on April 10-12 at Pennsylvania State College, as a continuation of the Conference on Computing Methods and the Phase Problem, which had been organized by Ray Pepinsky.

From all this it is apparent that, while the ACA is formally 25 years old, its roots range farther back. The ASXRED and the CSA are not the parents of the ACA, but rather they are earlier divisions of the ACA, so that our beginnings extend back at least to 1938 and 1941.

From this broader point of view, what has been accomplished until now? Perhaps most important is that the interests of the root societies in a journal devoted to crystallography was the stimulus which eventually launched the International Union of Crystallography and Acta Crystallographica. This came about in the following way: As president of the ASXRED in 1943, I realized the need of a vehicle to publish articles too long for the ordinary journal. Accordingly, I appointed a committee consisting of J. D. H. Donnay, George Tunell, and myself to see what could be done. We circulated a memorandum to the membership of the ASXRED sounding them out on their interest in a possible monograph series. They authorized us to go ahead. To finance the undertaking, I solicited contributions from companies who were in the business of making X-ray diffraction equipment and received support from The General Electric X-Ray Corp., Machlett Laboratories, North American Philips, and Picker X-Ray Corp. These contributions were placed in a revolving fund. The monographs were distributed free to all members of the ASXRED but sold to all others. Two monographs were published by the ASXRED before the advent of the ACA. The CSA published one monograph during the same period.

On instruction from the membership of the ASXRED, and as chairman of the Monograph Committee, I wrote on October 16, 1944 to H. Lipson, Secretary of the X-ray Analysis Group of Cambridge, England, telling them of our Monograph Series and informing them of our interest in establishing a journal. I expressed the hope that the X-ray Analysis Group would join with us in this project. Lipson called a meeting of that group on November 18, 1944 to consider this and other business. Eventually Sir Lawrence Bragg, chairman of the X-ray Analysis Group, suggested that the Americans send a delegation to England to discuss the possibility of publishing a journal and to consider the formation of an International Union of Crystallography. The meeting was eventually set for July 12 and 13, 1946. The American delegation included Fankuchen, Donnay, Germer, Harker, Wyckoff, McLachlan, Zachariasen and myself. From this meeting arose the International Union of Crystallography,Acta Crystallographica and plans for a new edition of the "International Tables."

Among the several noteworthy accomplishments of the ACA are the solution of numerous crystal structures whose reports have so filled the pages of Acta Crystallographica that the journal had to be split into two parts per volume and other material separated into another journal. It would be interesting to see an analysis of these contributions, but I make no attempt to do that here. I would, however, like to note that in one field of crystallography, the main channel has been outlined by members of the ASXRED, although contributions have come from many countries, namely, the direct methods of crystal-structure analysis.

I believe I had the honor of presenting the break which led to the hope of developing direct methods. At the Lake George meeting of the ASXRED in 1946 I presented the implication diagram. This results from a simple characteristic rotation and shrinking of the Harker section of the Patterson function. It has the property, in favorable space groups, of mapping the locations of atoms in a projection of the crystal structure. In less favorable space groups this desired result is accompanied by certain ambiguities and satellites. I demonstrated the use of the theory by solving the structure of the mineral nepheline, space group P6₃. That a structure could be solved by use of reflection magnitudes alone was a surprising result and it was greeted with no little incredulity. But Fankuchen immediately pointed out that since this could be done it implied that there must exist phase information hidden among the collection of reflection magnitudes. This was a stunning conclusion, for up to this time it had been believed that since the phases were experimentally unobservable, they were hopelessly missing and there was not any direct route to the solution of a crystal structure. By the time of the next ASXRED meeting at Ste. Marguerite in 1947, the Harker-Kasper inequalities were presented. These provided phase information under certain conditions, so there could no longer be any doubt that phase information was contained in the set of reflection magnitudes.

In subsequent meetings of the ASXRED many kinds of inequalities were reported. It is interesting that at the Conference on Computing Methods and the Phase Problem just preceding the first meeting of the ACA here in 1950, David Sayre showed that the comparison of the electron density with its square revealed that there existed some quite simple relations between the signs of certain structure factors. Sayre's conclusions inspired a spate of theoretical investigations of sign relations between structure factors. These culminated in the statistical work by Herbert Hauptman and Jerome Karle entitled "The Solution of the Phase Problem,"published as Monograph No. 3 of the ACA. Later this was followed by a long series of papers, mostly in Acta Crystallographica by Isabella Karle and J. Karle, which taught crystallographers a routine called the "Symbolicaddition method" which led to a direct determination of the crystal structure.

Although the "direct" route from diffraction intensities to the crystal structure is commonly thought to lead only through Fourier space, it may also be followed through Patterson space. In the same Conference on Computing Methods and the Phase Problem 25 years ago, I showed that a Patterson function can be decomposed into images of the crystal structure. In another paper in Acta Crystallographica entitled "A New Approach to Crystal-Structure Analysis" I presented imageseeking functions by which a Patterson function can be transformed into an approximation to the electron density function. Although many crystallographers have used this "direct" route through Patterson space, the route is less popular than the symbolic-addition method, probably because it has not been reduced to a computing routine. It is, however, a powerful "direct" method which has had no difficulty in solving an inorganic structure which has 15 non-heavy atoms and 20 oxygen atoms per asymmetric unit.

I have presented an outline of how the ACA arose from its two root societies, and some of the achievements of that period. Having solved some of the problems of the past so thoroughly that the solutions are available to other sciences as computer routines, let us not make the mistake of believing that crystallography has reached its zenith and is coasting downhill. Like all other sciences crystallography is open-ended, and the solution of crystal structures by diffraction is not its sole objective. I need only mention another phase problem as an example. It should be possible to theoretically predict the structure of a phase in any phase field, and not have to discover it experimentally. At present we cannot even do this for one-component systems. Understanding phase fields and their structures is one of the many problems which should engage our attention during the next quarter century. Ladies and gentlemen of the American Crystallographic Association, please present your report before the end of nineteen hundred ninety nine.