DUGi

Molecular structures of M2N22- (M and N = B, Al, and Ga) clusters using the gradient embedded genetic algorithm

http://dugi.udg.edu/item/http:@@@@hdl.handle.net@@10256@@8669

Al-4(2-) was the first discovered sigma + pi aromatic all-metal cluster. In the present work we analyze the molecular structure, relative stability, and aromaticity of lowest-lying isomers of related M2N22- (M and N = B, Al, and Ga) clusters, with special emphasis devoted to the cis (C-2v) and trans (D-2h) isomers of the M2N22- clusters. For such purpose, we start by performing the search of the global minimum for each cluster through the Gradient Embedded Genetic Algorithm (GEGA). Energy decomposition analyses and the calculated magnetic-and electronic-based aromaticity criteria of the lowest-lying isomers help to understand the nature of the bonding and the origin of the stability of the global minima. Such methodology should allow guiding future molecular design strategies

The authors are grateful to the Research Executive Agency of the European Research Council for financial support through the PIRSES-GA-2009-247671 project of the FP7-PEOPLE-2009-IRSES program. RI thanks the same organization for the postdoctoral fellowship received from the same project. Moreover, the following organizations are thanked for financial support: the Ministerio de Ciencia e Innovacion (MICINN, project numbers CTQ2011-23156/BQU and CTQ2011-25086/BQU), the Generalitat de Catalunya (project number 2009SGR637 and Xarxa de Referencia en Quimica Teorica i Computacional), and the FEDER fund (European Fund for Regional Development) for the grant UNGI08-4E-003. Excellent service by the Centre de Serveis Cientifics i Academics de Catalunya (CESCA) is gratefully acknowledged. The authors also are grateful to the computer resources, technical expertise, and assistance provided by the Barcelona Supercomputing Center - Centro Nacional de Supercomputacion. Support for the research of M. Sola was received through the ICREA Academia 2009 prize for excellence in research funded by the DIUE of the Generalitat de Catalunya. E.M. acknowledges financial support of the EU under the Marie Curie Career Integration grant (PCI09-GA-2011-294240) and the Beatriu de Pinos program from AGAUR for the postdoctoral grant (BP_B_00236). J. P. acknowledges the MICINN for the Ramon y Cajal contract. Helpful comments from Dr. Ferran Feixas are greatly acknowledged

Royal Society of Chemistry