Routes to carbon schwarzites from fullerene fragments

We investigated by tight-binding molecular dynamics the coalescence of fullerenic fragments and carbon clusters by following the evolution of the topological connectivity. Though different temperature variation protocols lead to irregular structures, their connectivity is found to stabilize at values corresponding either to three-branched schwarzites or tubulenes, indicating that longtime evolution at constant connectivity is potentially able to yield regular shapes. These results can be related to experiments on laser-induced transformations of fullerite occasionally yielding branched structures with a schwarzite shape.