biostudies-literatureUnknown13(1)Sowlati-Hashjin SRecent discovery of an unusual bond between Na and B in NaBH₃^- motivated us to look for potentially similar bonds, which remained unnoticed among systems isoelectronic with NaBH₃^-. Here, we report a novel family of collective interactions and a measure called exchange-correlation interaction collectivity index (ICI_XC; [Formula: see text]) to characterize the extent of collective versus pairwise bonding. Unlike conventional bonds in which ICI_XC remains close to one, in collective interactions ICI_XC may approach zero. We show that collective interactions are commonplace among widely used organometallics, as well as among boron and aluminum complexes with the general formula [M^a+AR₃]<sup>b-</supNature communications2069https://www.ebi.ac.uk/biostudies/studies/S-EPMC9018958biostudies-literatureCollective interactions among organometallics are exotic bonds hidden on lab shelves.PMC9018958Foroutan-Nejad CSowlati-Hashjin SKarttunen MSadek VMartin-Pendas ASadjadi SfalseCollective interactions among organometallics are exotic bonds hidden on lab shelves.Recent discovery of an unusual bond between Na and B in NaBH₃^- motivated us to look for potentially similar bonds, which remained unnoticed among systems isoelectronic with NaBH₃^-. Here, we report a novel family of collective interactions and a measure called exchange-correlation interaction collectivity index (ICI_XC; [Formula: see text]) to characterize the extent of collective versus pairwise bonding. Unlike conventional bonds in which ICI_XC remains close to one, in collective interactions ICI_XC may approach zero. We show that collective interactions are commonplace among widely used organometallics, as well as among boron and aluminum complexes with the general formula [M^a+AR₃]<sup>b-</sup2022-01-01T00:00:00Z2022 Apr2025-04-26T18:44:02.06Z2024-11-21T00:46:34.662ZS-EPMC90189583544058810.1038/s41467-022-29504-0