Researchers at Rice University (an active group working on graphene) demonstrate that every atom counts in graphene formation using DFT calculation of CVD process. They have highlighted the importance of carbon dimer for faster and better quality graphene growth. Overall, the study reveals the importance of mostly favored low energy paths for graphene formation.
http://news.rice.edu/2012/09/04/every-atom-counts-in-graphene-formation/
http://news.rice.edu/2012/09/04/every-atom-counts-in-graphene-formation/