It looks like fullerenes may have some as-yet undiscovered cousins: Novel forms of the elements predicted by simulation
Different structures of carbon e.g. graphite, diamond, or fullerenes possess remarkably different properties. Using their simulation technique, ETH researchers have predicted several new forms of carbon at atmospheric pressure.
Two of these are especially interesting in that they contain elements of both the graphite and the diamond structures and can be expected to possess unique hardness and electrical properties. Like fullerenes, these forms would require special conditions of synthesis — but once prepared, could become technologically important materials.
And it’s not only carbon that these guys seem able to predict new combinations for — they claim their simulation can predict the structure of any material at any temperature/pressure combination. If so, it should be interesting to see what other useful materials might emerge from this predictive capability.