Dihydrogen bond cooperativity in (HCCBeH)n clusters

8 pages, 9 figures, 9 tables.-- PACS: 31.15.ae; 31.15.E-; 31.15.bw; 36.40.-c; 31.30.jp; 31.15.amA theoretical study has been carried out on the clusters formed by the association of ethynylhydroberyllium (HCC-BeH) monomers. The monomer presents a linear disposition with a dipole moment of 0.94 D. Clusters from two to six monomers have been calculated for three different configurations (linear, cyclic with dihydrogen bonds, and cyclic with hydrogen bonds to the (pi)-cloud), the third one being the most stable. The electronic properties of the clusters have been analyzed by means of the atoms in molecules and natural bond orbitals methodologies. Cooperative effects, similar to the ones described for standard hydrogen bonded clusters, are observed in those configurations where dihydrogen bonds are the main interacting force.M. Solimannejad acknowledges the travel grant provided by CSIC and Arak University. This work was carried out with financial support from the Ministerio de Ciencia y Tecnología (Grant Nos. CTQ2006-14487-C02-01/BQU and CTQ2007-61901/BQU ) and Comunidad Autónoma de Madrid (Project MADRISOLAR, Reference No. S-0505 /PPQ/0225).Peer reviewe