title: Li-Filled, B-Substituted Carbon Clathrates.
abstract: Inside the cages of hypothetical carbon clathrates there is precious little room, even for the smallest atoms, such as Li-unless it is the Li(+) ion that is inserted, in which case a compensating negative charge should be distributed over the carbon cage. The hypothesis explored in this paper is that Li insertion can be achieved with appropriate B substitution within the framework. The resulting structures of 2Li@C10B2 (Clathrate VII), 8Li@C38B8 (Clathrate I), 7Li@C33B7 (Clathrate IV), 6Li@C28B6 (Clathrate H), and 6Li@C28B6 (Clathrate II) are definitely stabilized in theoretical calculations, especially under elevated pressure, as judged by enthalpy criteria and bond length metrics. Different strategies for B substitution (symmetry reduction, following the parent charge distribution, and substitution on the most weakened bonds, relieving stress on bond angles) are explored. Two possible competing channels for Li doping-B substitution, formation of LiBC and C-vacancies, are investigated.
authors.affiliation: Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.|Department of Chemistry, Carleton University , Ottawa, Ontario K1S5B6, Canada.
authors.forename: Tao
authors.initials: T
authors.lastname: Zeng
authors.affiliation: Baker Laboratory, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States.
authors.forename: Roald
authors.initials: R
authors.lastname: Hoffmann
authors.affiliation: Laboratory of Inorganic Chemistry, ETH Zürich , Vladimir-Prelog-Weg 1, CH-8093 Zürich, Switzerland.
authors.forename: Reinhard
authors.initials: R
authors.lastname: Nesper
authors.affiliation: Laboratory of Atomic and Solid Physics, Cornell University , Ithaca, New York 14853, United States.
authors.forename: N W
authors.initials: NW
authors.lastname: Ashcroft
authors.affiliation: Geophysical Laboratory, Carnegie Institution of Washington , 5251 Broad Branch Road NW, Washington, D.C. 20015, United States.
authors.forename: Timothy A
authors.initials: TA
authors.lastname: Strobel
authors.affiliation: Dipartimento di Chimica, Università degli Studi di Milano , 20133 Milano, Italy.|Samara Center for Theoretical Materials Science (SCTMS), Samara State University , Samara 443011 Russia.
authors.forename: Davide M
authors.initials: DM
authors.lastname: Proserpio