title: Extremely long Cu···O contact as a possible pathway for magnetic interactions in Na2Cu(CO3)2.
abstract: Chemical binding in a mixed copper sodium carbonate Na2Cu(CO3)2, a layered material showing ferromagnetic intralayer exchange and weak antiferromagnetic interlayer coupling, was examined within the topological analysis of experimental (from high-resolution X-ray diffraction) and theoretical (from periodic quantum chemical calculations) electron density functions in its crystal. Together with modeling of a superexchange pathway within the LSDA and DFT+U approach, the results obtained reveal a very weak Cu···O interaction (0.5 kcal/mol worth) between the copper-carbonate layers that is nevertheless stabilizing (bonding) and may serve as a possible pathway for antiferromagnetic interactions.
authors.affiliation: A.N. Nesmeyanov Institute of Organoelement Compounds, Russian Academy of Sciences, Vavilova Str., 28, 119991 Moscow, Russia.
authors.forename: Yulia V
authors.initials: YV
authors.lastname: Nelyubina
authors.forename: Alexander A
authors.initials: AA
authors.lastname: Korlyukov
authors.forename: Ivan V
authors.initials: IV
authors.lastname: Fedyanin
authors.forename: Konstantin A
authors.initials: KA
authors.lastname: Lyssenko