Graphitic quantum chemical calculations

While there is substantial theoretical interest in the electronic structure of forms of conjugated carbon beyond graphite (1), at the present time the polydiacetylenes (PDAs) provide the most accessible experimental systems with one-dimensional conjugated polymer chains available in fully ordered single crystal form. As such the PDAs occupy a key position among organic materials which exhibit phenomena indicating delocalized interactions in that quantum chemical calculations (2) estimate bandwidths... 

Figure 1 Thermodynamic cycle for the enthalpy of formation of methane (CH4) from the standard states of carbon and hydrogen (graphite and H2). The quantities in italics are calculated in typical thermochemical quantum chemical predictions.

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