Nature’s Missing Crystal – Found It!

K4 crystal

Diamond is not unique! Nature’s missing crystal discovered! A crystal as beautiful as diamond! Those were the themes running through dozens of articles in the media about a discovery made by Japanese mathematician Toshi Sunada of Meiji University. The original press release proclaimed that he had discovered a theoretical crystal structure with the same symmetry properties as diamond but with handedness, or chirality, and that this knocked the crown from diamond’s uniqueness.

Unfortunately, he soon discovered just how embarrassing press attention can be as chemists and crystallographers began filling his email inbox with messages alerting him to the existence of the exact same structure he was “predicting” already having been found. I asked Sunada about what happened.

“After my article appeared [in Notices of the American Mathematical Society; PDF file] a few people pointed out the oversight,” he told me, “They were rather sympathetic to that the difference of culture between mathematics and other sciences that leads to such ignorance.” He adds that although he hadn’t been aware of the known crystal structure until his modelling constructed it before his eyes, the people who contacted him were unaware of the history of his work in this area stretching back a decade. The original work that led to the discovery of the structure was done by AF Wells in the mid-1970s.

It highlights just how far apart different fields in mathematics and the sciences are despite efforts by various agencies and funding bodies to attempt to build multidisciplinary bridges. The debacle reminded me of how it took a mathematician colleague to point out to Harry Kroto and his colleagues that the structure of the all-carbon molecule buckminsterfullerene and the symmetry laid bare by their spectra was suggestive of a truncated icosahedron, a soccerball, in other words!

It makes me wonder what other discoveries have we missed because the sciences are no longer as joined up as they were in the heyday of the nineteenth century polymaths like Faraday. Put another way how much money is wasted re-inventing the wheel. Without wishing to criticise Sunada or the referees of the original paper, but if a chemical colleague happened to have seen his structural simulations they might have spotted th fatal flaw in the argument that much sooner. Perhaps the Scandinavian idea of hot-desking should be introduced into labs, hot-benching you might call it, to boost the potentially innovative cross fertilisation of ideas. Or, how about a cross-disciplinary approach to peer review, send to two experts and an additional referee in another field entirely if the paper claims true novelty.

Anyway, back to Sunada’s work. It may at first seem that here was merely a mathematician modelling something that chemists and materials scientists already knew, but although one half of his discovery was not a discovery at all because the structure was already known, one aspect of his work could save chemists a lot of searching in vain. “My result pins down that there are only two crystals having these properties,” he told me.

You can read more about Sunada’s discovery in my SpectroscopyNOW column this week.