Multichannel quantum defect theory simulations of the Rydberg spectra of HCO

Abstract

Multi-channel quantum defect theory (MQDT) is used to simulate the photoionization spectrum of HCO involving autoionizing Rydberg states converging on the v þ 2 ¼ 1, 2 and 3 thresholds. The simulations are compared with experimentally recorded spectra of resonances converging to the (03 1 0) state of HCO þ observed from the photoselected 3p 2 Å (030) K 0 ¼ 0, N 0 ¼ 0 intermediate state, and with spectra converging to the lower thresholds obtained by Mayer and co-workers. Matrix elements off-diagonal in l and v þ 2 are included to account for all channel interactions and autoionization. A reasonable agreement between experiment and theory is obtained by optimization of both the diagonal and off-diagonal elements of the quantum defect matrix, which are found to vary with the vibrational quantum number.

Scattering matrix approach to the dissociative recombination of HCO+ and N2H+

“…Therefore, using the simple formula v 2 |q 2 |v 2 = (v 2 + 1/2) and considering one quantum of excitation along a component of the degenerate mode and no quantum in the other normal modes, we obtain for v = (010) a reduced quantum defect μ vpσ,vpσ = 0.297, which is close to the value given by Brownbill and Softley. 50 More importantly, this suggests that changing v 2 by one quantum v 2 = 1 modifies the quantum defect by μ vpσ,vpσ ≈ −0.01, which is exactly what Brownbill and Softley 50 have found (see Table IV).…”

“…The optimization was then performed by manual adjustment On the other hand, we believe that there is a simple explanation for the value and behavior of the pσ quantum defect as a function of bending coordinate obtained in Ref. 50. Our calculations show that this state is only very weakly coupled to other electronic states through bending and that its strong quadratic shift (see Table II and Fig.…”

The Stark effect in the predissociating Rydberg states of NO

“…The effect of the electric field is incorporated into the traditional field-free formulation of MQDT (see for example [44]) by defining an external region (III in Figure 10 of [1]) where the potential experienced by the Rydberg electron is of the form (using atomic units)…”

Quasiclassical trajectory study on the integral cross-section and stereodynamics information of the reaction O ( 1 D) + H 2 (v = 0, j = 0 ) → OH + H

“…Because of its fundamental significance, this reaction has been widely investigated during the past 50 years. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16] A number of highly accurate global potential energy surfaces (PES) have been developed for this reaction, and its dynamics is mainly obtained on the ground state potential energy surface (PES) for the water molecule, 1 although the higher 2 1 A' state may also be involved through a conical intersection. Many experimental data, including rotation and vibration state distribution 2,3 of the product, total 4 and differential 6,7 reaction cross sections, and isotopic branching ratios, 8,9 * For correspondence thermal rate constants, 5,7,10 and non-adiabatic effects are now available for this system.…”

“…Reagent rotation increases reaction cross section monotonically for a few reactions such as O( 3 P) + H 2 12-14 and O( 3 p) + HCl. [15][16][17] Recently, Han 18-21 had used quasiclassical trajectories (QCT) method to investigate not only the reagent, product rotation and vibration but also about the vectors correlation. The product relative velocities (k, k ) and the rotational states ( j, j ) can offer a full picture of the scattering dynamics.…”