Structural and Electronic Properties of Low-Dimensional C-Nanoassemblies and Possible Analogues for Si (and Ge)

9 p.The delocalised nature of p-electrons in carbon-based compounds has opened a huge path for new fundamental and technological developments using carbon-based materials of different dimensionality (from clusters, to surfaces, nanotubes and graphene, among others). The success of this field has prompted the proposal that other inorganic structures based on B and N and more recently on Si and Ge could be formed with specific structural, mechanical, and electronic properties. In this paper we provide an analysis of the similarities of the two fields starting from the analysis of the Si6H6 molecule, the analogue of the benzene molecule but now being nonplanar. Then we move to the study of the two-dimensional (buckled) analogues of graphene but now formed by Si and Ge. Similarly, we look to nonplanar compounds based on boron and boron-carbon nitrogen composites. In particular, we focus on the mechanical properties of those new materials that exhibit a very high stiffness, resilience, and flexibility. Possible applications in the fields of catalysis, lubrication, electronic, and photonic devices now seem a likely by-product. We also address future directions triggered by the predicted superconducting properties of graphene, among other areas.This work has been supported also by the Spanish MEC (FIS2007-65702-C02-01), ACI-Promociona (ACI2009-1036), "Grupos Consolidados UPV/EHU del Gobierno Vasco" (IT-319-07), ETORTEK and the European Union through e-I3 ETSF (Contract: 211956), NANANODEVICES (IST-2006-029192), and THEMA (Contract: 228539) projects. The authors acknowledge support by the Barcelona Supercomputing Center, "Red Espanola de Supercomputacion", SGIker ARINA (UPV/EHU), Transnational Access Programme HPC-Europe++. Finally, it is a pleasure for N.H. March to thank professor P.M. Echenique for most generous hospitality at DIPC