You have to understand that the work I do is largely collaborative and the role I play is as a crystallographer. In these cases, the interest in the articles is largely due to the intellectual effort my collaborators have put into designing their experiments. Take, for instance, my 1996 paper with Crabtree that has the most citations (R.H. Crabtree et al., "A new intermolecular interaction: unconventional hydrogen bonds with element hydride bonds as proton acceptor," Account. Chem. Res. 29[7]: 348-54, July 1996). The large number of references on that paper are due exclusively to the interest generated by the work Crabtree did. I just come along and, as a crystallographer, prove to the world that they’ve actually done what they think they’ve done. I’m an essential part of it, but my major contribution is crystallography. That’s my role in about 90% of my publications. The other 10% is based on my own work.

  Do you think of yourself primarily as a crystallographer?

I would identify myself as an inorganic chemist who does crystallography. I hope that’s what’s chiseled on my tombstone someday. Crystallography is just a way to get somewhere. It’s not my primary interest. There are plenty of people in the world whose primary interest is crystallography, but I do not consider myself one of those.

  How did you end up developing your skills as a crystallographer?

I approached it originally from the synthesis end. I was trying to make new compounds that I hoped would have interesting physical properties and that might have applications in the world of materials science. This was 20, 25 years ago, and there weren’t that many crystallographers around who could help me characterize these materials. So I had to get into that business myself, adding that capacity to my own skills. I spent a sabbatical year learning crystallography at what was then SUNY Buffalo and is now called the University of Buffalo. I studied with Melvyn Churchill who is a world-famous crystallographer.

  Why was there such a shortage of crystallographers 20 years ago?

Well, not many people were equipped to do it, nor did they have the patience to, because it required a lot of time and a lot of effort. Now it’s been made much easier with the improvements in computing facilities and software. But when I was a graduate student in the sixties it took about nine months to do a single complete structure. Now you can do them in about two hours. The big change came with automation and computers. By the time I got started 20 years ago, it took about five days to do a single structure.

  How did you make the transition from doing your own structures to providing the service for others?

Simple. I had an X-ray defractometer that I wasn’t using 100% of the time. There were two people, in particular, who were very important because they were prominent chemists who believed in my skills and brought their work to me. One was Gregory Geoffrey. He is now president of the University of Iowa. The other is Russell Hughes, who is at Dartmouth.

  Have you noticed a correlation between how interesting you personally find the work and the number of citations it gathers?

There often is. The people who end up being highly cited are people doing prominent research. What often makes the difference between prominent and obscure research is the ability of people doing the work to promote what they’re doing in an interesting way that creates worldwide interest. Very often this is an entrepreneur’s game and you are selling yourself. People who are enthusiastically and capably selling their own work to the public are also obviously going to do a good job capturing my own attention, drawing me in and making me feel more involved.

  How often do you turn down collaborative offers?

I probably turn down three out of every four requests. I tend to work exclusively with two different groups of people. One group is people doing exciting, cutting-edge, frontier kind of research and the other group is people who really have no alterative but to seek outside help on their crystallography work because their institution is unable to support that kind of facility. People in the first group usually have a local facility, but choose to work with me, I hope, because they believe I can add something of value to the work they do. I also work with a great many local people, within 250, 350 miles of here, who probably couldn’t get the work done any other way.

  What is the greatest challenge to doing good crystallography?

Maybe two-thirds of what we do is fairly routine if we have good-quality crystals. The rest can be challenging. There are some similarities to working a jigsaw puzzle in a fog. As things fit together and the fog begins to lift, you begin to see patterns emerge; atoms connect to form structures. It can be quite stimulating. Sometimes it all falls straight into your lap and you hardly have to work at all. Then there are those days when nothing is obvious, nothing is simple, and you’re doing this complex connect-the-dots game. It is about as exciting an endeavor as one is capable of doing on an intellectual level.

What I’m really doing is generating a three-dimensional map of electron density. This means I have to connect the regions of high electron density in such a way as to make something that others would recognize as a molecule. That’s the connect-the-dots game. There are lots of ways you can connect them and some make chemical sense and some do not. You have to be a pretty good chemist to be in this business, and a lot of the fun is to see patterns that do emerge, particularly when you’re working with a new material and there are very few other clues to what it may be. A lot of people synthesize compounds and then come to me and say, "What the heck have I done?" They haven’t much of a clue, and I have to start without any preconceived ideas of what may emerge, except what I believe is chemically reasonable and what is not. I think the best crystallographers have had a long background in chemistry, usually inorganic chemistry. It provides the greatest relevant breadth of knowledge.

  How do you see crystallographic tools changing in the near future?

Well, there are many, many things going on. One of the main areas of progress is making more and more sensitive detectors for X-rays. We’re always plagued by the issue of crystal size and having to grow the crystals before we do the experiment. For every incremental increase in crystal size there is an exponential increase in the difficulty of growing the crystals. So that if I can get away with a tiny crystal, because my detectors are more sensitive, I’m in much better shape. When I got into this business I needed something about the size of a grain of salt when it comes out of the salt shaker. Now, I can take that same crystal and cut it into twentieths and still have something big enough. We’re literally doing structures on crystals now that are on the edge of being microscopic, that are invisible to the unaided eye.

  Finally, what, in your opinion, has garnered the 1996 Crabtree paper so many citations?

Well, hydrogen bonding is a subject of universal interest. Hydrogen bonding is, after all, one of the breakthrough concepts that led Watson and Crick to figuring out the structure of DNA. Until they thought of hydrogen bonding, or remembered it, they had no idea what held the helices together. And so hydrogen bonding has a prominent role in virtually all areas of descriptive chemistry. Therefore, the topic appeals to biochemists, inorganic chemists, organic chemists, and physical chemists. Everybody is interested in that. And here is a whole new kind of hydrogen bonding. A pair of compounds that you might not have ever thought would be engaged in hydrogen bonding until you read this paper. To prove that’s what it was, they had to have structural data and that’s what I was able to provide.