Εξειδίκευση τύπου :	Άρθρο σε επιστημονικό περιοδικό
Τίτλος:	Breaking covalent bonds in the context of the many-body expansion (MBE). I. The purported "first row anomaly" in XHn (X = C, Si, Ge, Sn; n = 1-4)
Δημιουργός/Συγγραφέας:	[EL] Τζέλη, Δήμητρα[EN] Tzeli, Demeter Xantheas, Sotiris S
Ημερομηνία:	2022-06-28
Γλώσσα:	Αγγλικά
ISSN:	0021-9606 1089-7690
DOI:	10.1063/5.0095329
Άλλο:	35778077
Περίληψη:	We present a new, novel implementation of the Many-Body Expansion (MBE) to account for the breaking of covalent bonds, thus extending the range of applications from its previous popular usage in the breaking of hydrogen bonds in clusters to molecules. A central concept of the new implementation is the in situ atomic electronic state of an atom in a molecule that casts the one-body term as the energy required to promote it to that state from its ground state. The rest of the terms correspond to the individual diatomic, triatomic, etc., fragments. Its application to the atomization energies of the XHn series, X = C, Si, Ge, Sn and n = 1-4, suggests that the (negative, stabilizing) 2-B is by far the largest term in the MBE with the higher order terms oscillating between positive and negative values and decreasing dramatically in size with increasing rank of the expansion. The analysis offers an alternative explanation for the purported "first row anomaly" in the incremental Hn-1X-H bond energies seen when these energies are evaluated with respect to the lowest energy among the states of the XHn molecules. Due to the "flipping" of the ground/first excited state between CH2 (3B1 ground state, 1A1 first excited state) and XH2, X = Si, Ge, Sn (1A1 ground state, 3B1 first excited state), the overall picture does not exhibit a "first row anomaly" when the incremental bond energies are evaluated with respect to the molecular states having the same in situ atomic states.
Τίτλος πηγής δημοσίευσης:	The Journal of Chemical Physics
Τόμος/Κεφάλαιο:	156
Τεύχος:	24
Θεματική Κατηγορία:	[EL] Φυσική και θεωρητική χημεία[EN] Physical and theoretical chemistry
Λέξεις-Κλειδιά:	Coupled-cluster methods Correlation energy Spin-spin interactions Many body systems Dissociation energy Gas phase Chemical bonding
Κάτοχος πνευματικών δικαιωμάτων:	© 2022 Author(s)
Όροι και προϋποθέσεις δικαιωμάτων:	All article content, except where otherwise noted, is licensed under a Creative Commons Attribution (CC BY) license (http://creativecommons.org/licenses/by/4.0/)
Ηλεκτρονική διεύθυνση με ανοικτή πρόσβαση (link):	https://pubs.aip.org/aip/jcp/article/156/24/244303/2841504/Breaking-covalent-bonds-in-the-context-of-the-many
Έχει σχέση με:	Erratum: "Breaking covalent bonds in the context of the many-body expansion (MBE). I. The purported 'first row anomaly' in XHn (X = C, Si, Ge, Sn; n = 1-4)" [J. Chem. Phys. 156, 244303 (2022)]
Εμφανίζεται στις συλλογές:	Ινστιτούτο Θεωρητικής και Φυσικής Χημείας (ΙΘΦΧ) - Επιστημονικό έργο