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Title: High-level ab initio composites: thermochemical bond dissociation energies for vanadium species
Bond dissociation energies (BDE) are key descriptors for molecules and are among the most sought-after properties in chemistry. Despite their importance, the accurate prediction of BDE’s for transition metal species can be particularly daunting for both experiment and computation. Experimental data has been limited and, when available, often has large error bars, making the critical evaluation and identification of suitable computational methods difficult. However, recent advancements in the experimental determination of BDE’s with techniques such as Velocity Map Imaging and 2 Photon Ionization now provide useful gauges for computational strategies and new methodologies, providing energies with unprecedented accuracies. The vanadium diatomics (VX, X=B, C, N, O, F, Al, Si, P, S, Cl) have been challenging for computational chemistry methods, and, thus, a new experimental gauge enables methods to be reevaluated and developed for these species. Herein, the super-correlation consistent Composite (super-ccCA or s-ccCA), a new thermochemical scheme centered around CCSD(T)/complete basis set (CBS) limit computations with additional contributions that account for scalar-relativistic effects, and coupled cluster contributions beyond CCSD(T) up to quintuple excitations has been considered. The agreement between determinations made by the s-ccCA scheme and by recent experiment is excellent, demonstrating the utility of the new approach in addressing challenging metal systems, even those of multireference nature. In light of recent experimental BDE’s, the longstanding correlation consistent composite approach (ccCA) is also evaluated for the VX species and find that the mean absolute deviation (MAD) is greatly reduced compared to previously used experimental values.  more » « less
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Author(s) / Creator(s):
; ;
Publisher / Repository:
Taylor & Francis
Date Published:
Journal Name:
Molecular Physics
Subject(s) / Keyword(s):
Electronic structure transition metals thermochemistry ab initio composite s-ccCA
Medium: X
Sponsoring Org:
National Science Foundation
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