Dipole moment surfaces and the mid- and far-IR spectra of N2-Ar

Abstract

An improved theoretical long-range dispersion plus induction dipole moment surface for N 2-Ar is presented, and detailed numerical simulations are used to test its predictions against experimental far-IR and mid-IR spectra using two previously-reported potential energy surfaces. As was found in earlier work on the mid-IR spectrum using a pure induction dipole surface, the MMSV mod potential of Jäger et al. ͓J. Chem. Soc. Faraday Discuss. 97, 105 ͑1994͔͒ yields distinctly better agreement with both experiments than does the XC-3 potential of Dham et al. ͓J. Chem. Phys. 103, 8477 ͑1995͔͒. However, the new dipole surface yields slightly poorer agreement with certain features of the experimental mid-IR and far-IR spectra, which suggests that the existing theoretical values and derivatives with respect to the bond length of some of the permanent moment and ͑hyper͒polarizability properties of N 2 need improvement.

Future of computational molecular spectroscopy—from supporting interpretation to leading the innovation

“…10 The nitrogen diatomic molecule (N 2 ) does not possess a permanent dipole moment, so that the IR active spectral transitions of the complex are produced due to small induction and dispersion effects of the Ar atom interacting with the N 2 diatom. 10 Another CMS leading innovation case is the decade long theory guided (synchrotron sourced) spectroscopic study of ferrocene (Fc). [27][28][29][30][31][32][33][34][35][36][37] The theoretical IR spectral discovery of the more stable Fc eclipsed conformer (D 5h ) 27 shed a light on Fc studies, led and suggested several new measurements of Fc and its derivatives.…”

“…2, 9 and the theoretically developed dipole moment function of the VdW complex. 10 The nitrogen diatomic molecule (N 2 ) does not possess a permanent dipole moment, so that the IR active spectral transitions of the complex are produced due to small induction and dispersion effects of the Ar atom interacting with the N 2 diatom. 10 Another CMS leading innovation case is the decade long theory guided (synchrotron sourced) spectroscopic study of ferrocene (Fc).…”

“…9 IR spectroscopy is accessible for almost all materials, the measurements which require small amount of sample are easy, fast and less expensive. IR spectroscopy is for polar compounds, 9–11 however. It does not provide information for molecular formula and usually needs to be employed in conjunction with other techniques.…”

Periodic Dispersion-Corrected Approach for Isolation Spectroscopy of N2 in an Argon Environment: Clusters, Surfaces, and Matrices

“…The present contribution examines the case of an N 2 molecule interacting with small Ar clusters, surfaces or embedded into an Ar matrix. Because of its importance for atmospheric and planetary processes [21,22], the Ar-N 2 cluster has been widely studied both theoretically [23][24][25][26][27][28][29][30][31][32][33][34][35] and experimentally [36][37][38][39]. These studies have provided an accurate characterization of this complex, of its potential energy surface and of its vibrational and rotational spectra.…”

“…The present contribution examines the case of an N 2 molecule interacting with small Ar clusters, surfaces or embedded into an Ar matrix. Because of its importance for atmospheric and planetary processes, , the Ar–N 2 cluster has been widely studied both theoretically − and experimentally. − These studies have provided an accurate characterization of this complex, of its potential energy surface and of its vibrational and rotational spectra. In particular, they established the existence of two minima of Ar–N 2 : a linear structure and a T-shaped structure, located in shallow potential wells (a few tens of cm –1 ).…”