Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Cooperative stability, many-body expansion, and σ-aromaticity of (LiH)n clusters (n = 1-6): A CCSD(T) study at the complete basis set limit
Δημιουργός/Συγγραφέας:	Semidalas, Emmanouil Drakopoulos, Filippos Routsi, E Alexandros Tzeli, Demeter
Ημερομηνία:	2026-07-28
Γλώσσα:	Αγγλικά
ISSN:	0021-9606 1089-7690
DOI:	10.1063/5.0336948
Άλλο:	42489404
Περίληψη:	We investigated the energetics and bonding of lithium hydride clusters (LiH)n (n = 1-6) using a composite ab initio scheme inspired by W2 theory to achieve sub-kcal/mol accuracy. This approach combines CCSD(T) results extrapolated to the complete basis set limit with a rigorous treatment of core-valence correlation, scalar relativistic effects, and the diagonal Born-Oppenheimer correction. Our results show that while Hartree-Fock theory captures the primary electrostatic binding, correlation effects are crucial for determining the energetic preference of compact isomers over cyclic rings. A parallel density functional theory study shows that while standard hybrid functionals like B3LYP-D4 and M06-2X exhibit larger deviations, the double-hybrid revDSD-PBEP86-D4 functional closely matches our benchmarks, delivering sub-kcal/mol accuracy. Structural and chemical bonding analyses, including intrinsic bond orbital, nucleus-independent chemical shift, and many-body expansion (MBE) methods, reveal high ionic character and multi-center bonding (3c-2e and 4c-2e) within the (LiH)n clusters. MBE analysis of the interaction energy of the monocyclic clusters with respect to the LiH molecules reveals that the two- and three-body terms are consistently negative (stabilizing), while all higher-order terms are negligible. We find that σ-aromaticity in these systems is predominantly local and bond-centered. As the rings expand, the interior becomes magnetically decoupled from the σ-skeleton, precluding the formation of a global ring current. These results establish definitive benchmarks for the stability of prototypical electron-deficient clusters.
Τίτλος πηγής δημοσίευσης:	The Journal of chemical physics
Τόμος/Κεφάλαιο:	165
Τεύχος:	4
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry [EL] Ατομική φυσική (συμπ. μοριακή φυσική, σχετικότητα, κβαντική θεωρία και φυσική στερεάς κατάστασης)[EN] Atomic physics (Incl. molecular physics, relativity, quantum theory, and solid state physics)
Λέξεις-Κλειδιά:	Computational chemistry Many-body expansion Chemical bonding σ-aromaticity
Χρηματοδότης:	Hellenic Foundation for Research and Innovation (H.F.R.I.)
Αναγνωριστικό χρηματοδοτικού προγράμματος:	21044
Ηλεκτρονική διεύθυνση στον εκδότη (link):	https://doi.org/10.1063/5.0336948
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο