Bob Parr - Teacher, Collaborator, Friend
A Personal View
R. Pariser & Co., Inc. 851 Old Public Road, Hockessin, DE 19707-9631
It is indeed my privilege to have this opportunity to write a few words on the occasion of the publication of this volume honoring the work of my teacher, collaborator, and
friend, Bob Parr.
My first contact with Bob as teacher occurred at the Chemistry Department of the
University of Minnesota where we both were graduate students. Bob had just finished
his requirements for his PhD in 1947 with Professor Bryce Crawford, and he stayed
on for a year to teach the graduate course in thermodynamics. Professor MacDougall,
who normally taught this course, may have been away on sabbatical that year. In his
characteristic style to search for new and elegant ways, Bob introduced an additional and memorable aspect to this course. He embellished it with the methodology of
Carathéodory - an approach which added unique perception and beauty to a subject
which among us graduate students had the reputation of being both obscure and dull.
Now that more than forty years have gone by, I still recall the deep satisfaction whichI had experienced in learning thermodynamics the Parr way.
In late 1950, I started work at the Jackson Laboratory of the Du Pont Company,
where I had accepted a position. Several months later, in my innocence — since my
thesis research had been essentially experimental and I had little in the way of formal theoretical training — I started a rather ambitious project on applying molecular orbital theory in order to help the large organic synthetic effort which was dominant in our
Laboratory. My primary objective was to develop theoretical tools which would be
helpful in correlating the color and photostability of organic dyes with their structure. At the time, a large program was in progress to synthesize dyes suitable for the new synthetic fibers which were then being developed.
It soon became obvious to me that the existing theoretical models at the time, such as the Hückel model, were far from adequate in meeting my objectives. It was then
that I had the brilliant idea to engage Bob Parr as my “consultant,“ for which I now happily take credit. When I first apprised Bob of my intentions, he gave me serious
encouragement. His attitude greatly strengthened my confidence in proceeding with
this project. In retrospect, knowing what he must have known at that time about
the lack of practicality and accuracy of the more advanced theoretical methods, he
displayed both the courage and vision which enabled us to move forward in our joint
During this phase, Bob was also my patient teacher in instructing me in the
methods of the “nonempirical“ molecular orbitals theories. More than any teacher
that I ever had, he understood my questions — no matter how awkwardly they were
asked — and he answered them in a way which was patently clear and fully complete.
He made me feel more than once that he had brought me up to the level of his own
understanding and to that of an equal rather than his “student.“ This, I feel, is the mark of a great teacher.
Our collaboration on the development of our new semi-empirical theory has been
well documented in this very Journal and honored by a special edition [1,2]. In its
full intensity, our work together lasted only about three years, covering the period 1951—1953. To me, it was the highlight of my scientific contribution during my thirty
eight year career with Du Pont. To Bob it was a relatively short period in a long
and brilliant scientific career, an achievement to which this volume is dedicated. The many papers documented herein will clearly attest that I was fortunate to be one of
many to benefit from association with such an outstanding man.
Over a period of more than forty years, Bob has been my good friend. My wife
and I have enjoyed visiting Jane and Bob in their magnificent, unique home which
they designed and built in Chapel Hill. This home speaks well to their character and excellent taste. lt is centered around a hexagon which symbolizes the structure of
benzene, a molecule which has intrigued Bob over many years in his career. The
home also reflects the Parr‘s strong international background and interests, ranging from his own early experiences in Beirut to his family ties in Japan. This too is of
special appeal to me, in view of my own early life in the Far East.
As a friend, Bob has always stood by me, he has recognized me, and he has
promoted me. To this day, I feel that he is someone that I can always count upon. He has made me feel very special. I also know that he has kept in touch regularly with
all his students and collaborators spread all over the world, and that he has been a
special friend to all of them as well. I am sure that all will agree that as a scientist,
teacher, and friend, Bob Parr is truly a champion.
 R. Pariser, Int. J. Quantum Chem. 37, 321 (1990).
 R.G. Parr, Int. J. Quantum Chem. 37, 327 (1990).
Last updated : Mar. 10, 2002 - 21:15 CET