Potential energy curves for the interaction of Ag($\mathbf {5}{\bm s}$5s) and Ag($\mathbf {5}{\bm p}$5p) with noble gas atoms

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We present a theoretical study of elastic and rotationally inelastic collisions of NH 3 and ND 3 with rare gas atoms (He, Ne, Ar, Kr, Xe) at low energy. Quantum close-coupling calculations have been performed for energies between 0.001 and 300 cm −1 . We focus on collisions in which NH 3 is initially in the upper state of the inversion doublet with j = 1, k = 1, which is the most relevant in an experimental context as it can be trapped electrostatically and Stark-decelerated. We discuss the presence of resonances in the elastic and inelastic cross sections, as well as the trends in the inelastic cross sections along the rare gas series and the differences between NH 3 and ND 3 as a colliding partner. We also demonstrate the importance of explicitly taking into account the umbrella (inversion) motion of NH 3 in order to obtain accurate scattering cross sections at low collision energy. Finally, we investigate the possibility of sympathetic cooling of ammonia using cold or ultracold rare gas atoms. We show that some systems exhibit a large ratio of elastic to inelastic cross sections in the cold regime, which is promising for sympathetic cooling experiments. The close-coupling calculations are based on previously reported ab initio potential energy surfaces for NH 3 -He and NH 3 -Ar, as well as on new, four-dimensional, potential energy surfaces for the interaction of ammonia with Ne, Kr, and Xe, which were computed using the coupled-cluster method and large basis sets. We compare the properties of the potential energy surfaces corresponding to the interaction of ammonia with the various rare gas atoms. C 2015 AIP Publishing LLC. [http://dx

Section: A Ab Initio Calculationsmentioning

confidence: 99%

Scattering of NH3 and ND3 with rare gas atoms at low collision energy

Loreau

Avoird²

2015

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“…Core-valence interactions can indeed alter the interaction energy significantly for heavy noble gases. 44 Twenty-six electrons were correlated in these calculations, which become prohibitively expensive with large basis sets. As can be seen from the last column of Table I, the effect is rather small (less than 0.4%) and can be neglected.…”

mentioning

confidence: 99%

Potential energy surface and bound states of the NH3–Ar and ND3–Ar complexes

Loreau

Liévin

Scribano

et al. 2014

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Interaction of the NO 3pπ Rydberg state with Ar: Potential energy surfaces and spectroscopy J. Chem. Phys. 138, 214313 (2013) A new, four-dimensional potential energy surface for the interaction of NH 3 and ND 3 with Ar is computed using the coupled-cluster method with single, double, and perturbative triple excitations and large basis sets. The umbrella motion of the ammonia molecule is explicitly taken into account. The bound states of both NH 3 -Ar and ND 3 -Ar are calculated on this potential for total angular momentum values from J = 0 to 10, with the inclusion of Coriolis interactions. The energies and splittings of the rovibrational levels are in excellent agreement with the extensive high-resolution spectroscopic data accumulated over the years in the infrared and microwave regions for both complexes, which demonstrates the quality of the potential energy surface. © 2014 AIP Publishing LLC.

“…All states of interest correlate with ground state Ar atoms plus low-lying 4d 10 5s ( 2 S), 4d 10 5p ( 2 P) and 4d 9 5s 2 ( 2 D) terms of Ag. Qualitatively similar curves exist for the other Ag-RG complexes [15] although Loreau et al recently showed that the excited state potentials show marked deviation from Morse functions when spin-orbit coupling is included. The A states of Ag-He and Ag-Ne are particularly anomalous supporting double well structures.…”

Section: Introductionmentioning

confidence: 56%

“…[14] The same states have recently been the subject of a detailed computational study at the spin-unrestricted coupled cluster level (UCCSD(T)) by Loreau et al. [15] A different excited state labelling is employed by Loreau et al but we have adopted labels consistent with Brock and Duncan. All states of interest correlate with ground state Ar atoms plus low-lying 4d 10 5s ( 2 S), 4d 10 5p ( 2 P) and 4d 9 5s 2 ( 2 D) terms of Ag.…”

Section: Introductionmentioning

confidence: 99%

Dissociation energies of Ag–RG (RG = Ar, Kr, Xe) and AgO molecules from velocity map imaging studies

Cooper¹,

Kartouzian

Gentleman³

et al. 2015

The near ultraviolet photodissociation dynamics of silver atom -rare gas dimers have been studied by velocity map imaging. Ag-RG (RG = Ar, Kr, Xe) species generated by laser ablation are excited in the region of the C ( 2  + )  X ( 2  + ) continuum leading to direct, near-threshold dissociation generating Ag* ( 2 P 3/2 ) + RG ( 1 S 0 ) products. Images recorded at excitation wavelengths throughout the C ( 2  + )  X ( 2  + ) continuum, coupled with known atomic energy levels, permit determination of the ground X ( 2  + ) state dissociation energies of 85.9 ± 23.4 cm -1 (Ag-Ar), 149.3 ± 22.4 cm -1 (Ag-Kr) and 256.3 ± 16.0 cm -1 (Ag-Xe). Three additional photolysis processes, each yielding Ag atom photoproducts, are observed in the same spectral region. Two of these are markedly enhanced in intensity upon seeding the molecular beam with nitrous oxide, and are assigned to photodissociation of AgO at the two-photon level. These features yield an improved ground state dissociation energy for AgO of 15965  81 cm -1 , which is in good agreement with high level calculations. The third process results in Ag atom fragments whose kinetic energy shows anomalously weak photon energy dependence and is assigned tentatively to dissociative ionization of the silver dimer Ag 2 .3