Inventory on innovative research:: the case of C3N4

Two prominent examples of the interaction between predicting and failing to synthesize new inorganic materials include metallic hydrogen and the so-called "harder than diamond" form of C3N4. In both cases there has been much speculation and calculation but years of experimentation have failed to produce the desired phases, and the intriguing interplay continues. This note is a brief appraisal of the status of the claims regarding C3N4 made by counting and analyzing published papers on the topic, in an attempt to inventory and evaluate "innovative research" on materials.