In:
The Journal of Chemical Physics, AIP Publishing, Vol. 134, No. 6 ( 2011-02-14)
Abstract:
We present a detailed theoretical investigation on the dissociation energy of CuO+, carried out by means of coupled cluster theory, the multireference averaged coupled pair functional (MR-ACPF) approach, diffusion quantum Monte Carlo (DMC), and density functional theory (DFT). At the respective extrapolated basis set limits, most post-Hartree–Fock approaches agree within a narrow error margin on a De value of 26.0 kcal mol−1 [coupled-cluster singles and doubles level augmented by perturbative triples corrections, CCSD(T)], 25.8 kcal mol−1 (CCSDTQ via the high accuracy extrapolated ab initio thermochemistry protocol), and 25.6 kcal mol−1 (DMC), which is encouraging in view of the disaccording data published thus far. The configuration-interaction based MR-ACPF expansion, which includes single and double excitations only, gives a slightly lower value of 24.1 kcal mol−1, indicating that large basis sets and triple excitation patterns are necessary ingredients for a quantitative assessment. Our best estimate for D0 at the CCSD(T) level is 25.3 kcal mol−1, which is somewhat lower than the latest experimental value (D0 = 31.1 ± 2.8 kcal mol−1; reported by the Armentrout group) [Int. J. Mass Spectrom. 182/183, 99 (1999)] . These highly correlated methods are, however, computationally very demanding, and the results are therefore supplemented with those of more affordable DFT calculations. If used in combination with moderately-sized basis sets, the M05 and M06 hybrid functionals turn out to be promising candidates for studies on much larger systems containing a [CuO] + core.
Type of Medium:
Online Resource
ISSN:
0021-9606
,
1089-7690
Language:
English
Publisher:
AIP Publishing
Publication Date:
2011
detail.hit.zdb_id:
3113-6
detail.hit.zdb_id:
1473050-9
Bookmarklink
