Leading the computational chemistry field
John Murphy profiles Professor Henry Schaefer, a leading light in theoretical computational chemistry at the University of Georgia
There are very few names in theoretical computational chemistry bigger than Professor Henry 'Fritz' Schaefer. He has published more than 1,000 papers on the subject and written most of the best-known books. He has a research team of about 25 at the University of Georgia, which continues to astound the world of chemistry with exactly what can be derived using computational techniques. He started his career by overthrowing previous notions about simple molecules like methylene. During the past 30 years he has worked his way up the complexity scale and is now starting to look at parts of DNA.
He is renowned for his charm and attracts huge crowds to his lectures during the three months he has spends every year travelling the world. He has caused some controversy by straying into the world of connections between science and Christianity, but he still continues to lecture on that subject as well as chemistry.
Nicholas Handy, who was professor of Quantum Chemistry at Cambridge University until his recent retirement, says Schaefer was a prolific lecturer and a great communicator. His lectures to undergraduates were legendary and his lectures around the world will often be to a university's entire chemistry department.
He says: 'He is a bundle of energy and, over the years, he has been a tremendous promoter of theoretical computational chemistry. Those outside the United States are always using him as a reference. He knows absolutely everybody in the field. He has not received the recognition the bulk of us think he should have received in the United States, because he is not a member of the National Academy. He has received all the recognition that he could get from the theoretical chemists, but the broader chemists are jealous.
'In my view he has always been a user of the methodology that has been developed for this science. One could not say that he developed the methodology and that may be a reason why he has not received the recognition he deserves. The bulk of his 1,000 papers demonstrate the power of the subject; rather than pick out one, I would prefer to look at the weight of them all and the contribution they have made to the field, which is showing that computational theoretical chemistry can lead to an understanding of molecules and their interactions.
'In my view he is a very nice man indeed, I have never found any difficulty with him at all. He has bags of personality and, while his health was not great these last five years, he seems to be restored now.'
Schaefer was born in Grand Rapids, Michigan, just as the Second World War was ending. His parents had distant German ancestry so they nicknamed him 'Fritz' - a name that has stuck. His father was a civil engineer and the family moved to Syracuse, NY and Menlo Park, CA, before moving back to Grand Rapids when he was a teenager.
He was very keen on sport, in particular basketball, and as a child he dreamed of being a professional, but when he did not grow enough he changed his mind. He says: 'I had a great desire to be a basketball star but it didn't work out. I was pretty good up to about 14 years old, but that was kind of the end of it. When I didn't grow seven feet tall and couldn't jump three feet up in the air and run fast, there was no hope.'
His best subject at school was mathematics and his dream, when he went to MIT, was to end up as a maths teacher. He soon decided to change subjects. He says: 'My first year at MIT was very difficult. I got four Bs and one C. I had never gotten a C in my life before, so that was difficult and I was not sure how successful I was going to be until my second year, when I started getting As. What was happening in the first year is that things were getting normalised. I was in class with people from the Bronx School of Science who were really high-powered, and had a few years of university-level classes before they got to MIT. I'm not really sure why I changed to chemistry; maybe it was a bit easier. By the end of the second year I was doing well enough that I could go into whatever I enjoyed most - and what I enjoyed most was chemical physics.'
He eventually did well enough to attract offers for a PhD programme. He wanted to go back to California, where he had been as a child, and applied to CalTech. He was accepted, but then he and his then fiancée decided that they were going to get married, despite her not having finished her undergraduate years. He contacted Stanford University and told them of this problem and they accepted her as a transfer and him as a graduate student in a single package. He worked in the laboratory of Frank Harris.
He says: 'By then I knew I wanted to be a quantum chemist, and there were two people at Stanford doing quantum chemistry. Frank was the one who was the most welcoming. It was very primitive at the time. The other person I spoke to was Harden Mcconnell, who went on to become a famous biochemist, told me that trying for fairly rigorous solutions to Schrödinger Equations was hopeless. Maybe some day people could do diatomic lithium hydride, but there was no hope for the field beyond that so the situation was pretty pathetic. I was in love with the subject. Most of my PhD thesis was on first-row atoms, but I published one paper on diatomic oxygen, which turned out to be quite good. So we were heading in the right direction - but just getting started.'
After completing his PhD he did three interviews; Berkeley was the only university that offered him a job. They had no theoretical chemists and he was one of two they hired. He started using the new-fangled techniques of computation but, at the time, there was little computing power available to scientists for such work. He started borrowing down time from a Univac 1108 supercomputer owned by the private University Computing Company. Through a friend, he was able to run calculations in the middle of the night when the computer was not being used.
He says: 'We didn't know if this arrangement was going to work, but we got started on it. It didn't seem too natural to be able to solve these problems through computation, but we thought it was within range. We knew quantum mechanics could work; it was just a question of whether we could apply it.'
What really got Schaefer noticed was a 1970 paper on the structure of methylene. It was previously though to be a straight line molecule, but he used computational techniques to show that in fact there was a 134-degree angle.
'It was like an engine. Just a few months after we reported our work in the Journal of the American Chemical Society the distinguished experimentalist, Ed Wasserman, than at Bell Labs, showed that we were right. It didn't really have time to be controversial, because Wasserman came out just three months later. There was a lot of discussion about it, because we had upended the most famous spectroscopist in the world. But it all took place so fast. The referees made us moderate the language of the paper a little bit. I don't think that Wasserman believed he was going to show us to be right.'
By producing such a spectacular result that was confirmed by experiment, Schaefer not only launched his own career, but boosted the whole field of computational quantum chemistry. He set out to tackle increasingly difficult problems and to publish more papers that would astound conventional wisdom. He started receiving prizes, but resources were still scarce. He rose up the scale to become a full professor at Berkeley within nine years. He scratched around for computing resources and eventually persuaded the National Science Foundation to fund a computer for chemistry research. He eventually got a Datacraft 6024/4 with nearly 0.2Mb of memory and a 54Mb removable-pack disk drive. The main rival at the time was the Digital Equipment PDP range, but Schaefer decided he needed the 48-bit words precision.
He says: 'Datacraft was a fly-by-night company that had the idea of 24-bit words, which we used in double precision. It seemed to offer so much more than anything else. It was a rocky ride at first; it took three months just to get it to work. The engineer eventually had to put a piece of copper foil on one of the boards to get it to work. We did a lot of chemistry with that machine.'
Scientific success, of course, did not put food on the family table, so Schaefer had started looking around for other positions. In 1979 he was offered a job at the University of Texas. He made the move, but with the opportunity to return if things did not work out.
He says: 'The University of Texas is an institution that has always seemed promising. They allowed me to start an institute for theoretical chemistry, which was very exciting. Berkeley did not want me to resign because they were sure I was going to be unhappy and come back, which is what happened. But it was a great opportunity and we had a great year there. In terms of personal relations, I am still not popular in Texas; they think I really didn't give it a fair try. Candidly, Berkeley doubled my salary and bought a new $200,000 computer and we were quite comfortable with life in Berkeley.'
In 1987 he did finally move, when he was made an offer he could not refuse by the University of Georgia. By this time he had four children and he wanted to move to a quieter area of the world. They created an institute for him and said eventually they would build a new building for him, which took about 10 years.
He says: 'They did everything they promised to do. The building is still the only one ever constructed specifically to do computational chemistry research; it's a real jewel. They had never recruited anyone away from Berkeley or Harvard, so it made good publicity for them and would inject some life in the chemistry department and the university as a whole. Most of my colleagues at Berkeley took me out to lunch and told me I had lost my mind.'
Colleagues were worried that in Georgia he might be away from the mainstream, but they need not have worried. Firstly, his department became the mainstream and is now probably the largest team in the world devoted to computational chemistry. His output of papers and books has continued to be prolific and he became the sixth most-cited chemist in the world for the period 1981-1997, according to ISI. He has also embarked on a remarkable series of guest lectures covering not just most of the US, but also parts of the world that have rarely seem a scientist of his calibre.
One of his greatest achievements has been his diaspora of research students. Of 83 PhD students, many are now professors in their own right, four have started their own companies and countless others have taken the techniques of computational chemistry into industrial laboratories all over the world.
He says: 'The most important thing is to bring new and younger people into the field and it's great fun sitting back and watching what these people can do.'
He says that one of the best things about his current job is that he does not have to do any university administration and can concentrate on teaching and research. His current research interests are focused on combustion and the stuff of life itself.
He says: 'We have had a lot of support from the Department of Energy for work on combustion chemistry and we have made some advances that have really surprised people, for example concerning the oxidation of the ethyl radical. It's a simple system, but quite important in combustion. We discovered five or six years ago that a mechanism that surprised everyone in the combustion business and has proved quite helpful. We have support from the National Science Foundation and we are looking at little pieces of DNA; sub-units. That has been fruitful. We are at nucleotide pairs at the moment, which is in the ballpark of 100 atoms. This is going to grow, because computers become faster and faster. It's very challenging, but biology is a much more approximate science so you can get away with things that you can't with something like combustion.'
Apart from computational chemistry his other favourite subject for lectures is the relationship between science and christianity. He teaches a freshman course entitled 'Science and Christianity: Conflict or Coherence?' and has recently published a book of the same title. He stresses that he has no time for people who promote 'creation science' or other extreme dogmas. He simply thinks it is important that so many of the great scientists in history have also been Christians and that there may be a connection.
He says: 'I am coming from the direction of coherence. When I was at Berkeley I became a Christian and over the years I started becoming interested in the interface between science and Christianity. That book is much more controversial than anything I have ever done in science. I think that being a Christian gives you a sense of wonder and awe, which I guess you can get in some other way.
'I have debated this subject with Steve Weinberg [1979 Nobel Prize winner for Physics] and I had a number of arguments for why I thought a scientist should believe in God. He's an atheist and there is only one of these arguments that he liked: this whole business about the intelligibility of the universe and that it's possible to understand nature with such amazing success through mathematical physics. He said that was something that really bothered him.'