Revisiting the photoabsorption spectrum of NH3 in the 5.4–10.8 eV energy region

Abstract

Lanczos-based equation-of-motion coupled-cluster singles-and-doubles approach to the total photoionization cross section of valence excited states

Ultraviolet Absorption Cross-Sections of Ammonia at Elevated Temperatures for Nonintrusive Quantitative Detection in Combustion Environments

“…2a) based on the Beer-Lambert law in which the absorbance was obtained from the experimental measurement using the high-resolution spectrometer, the NH 3 concentration was 22 ppm, and the optical path length was 183 mm. It shows a good agreement with the most recently reported absorption cross-section data in the work of Limão-Vieira et al 38 The UV spectra covered the range of wavelengths from 190 nm to 230 nm. The absorption was attributed to theà 1 A 00 2 X 1 A 0 1 transition of NH 3 , corresponding to a progression in the umbrella bending mode, n 2 .…”

“…The decrease was caused by the distribution of the ground state and has been fitted by Davidson et al 46 Due to the low sensitivity of the spectrometer at 193 nm, the high measurement uncertainty led to the divergence of the simulation and experimental results. The absorption cross-section obtained from the present work at room temperature is close to the ones from the most recent work provided by Limão-Vieira et al 38 and Cheng et al, 39 and it is believed that the values of the present work at different high temperatures also have a good confidence.…”

“…The absorption spectrum appeared in the form of discrete vibronic bands, spaced by approximately 900 cm À1 , above an apparent continuum, and the details of the key features have been widely studied. 38,55 The gas in the heating tube was heated up to 390 K, 490 K, and 590 K with a constant NH 3 concentration. Thus, the absorption cross-section at different temperatures was derived based on the Beer-Lambert law using the measured absorbance at the corresponding temperature.…”

Pulsed Electron-Electron Double Resonance (PELDOR) and Electron Spin Echo Envelope Modulation (ESEEM) Spectroscopy in Bioanalysis

“…A final spectrum is obtained through concatenation of the small sections, demonstrated in Fig. 2.14 for the spectrum of ammonia (Limão-Vieira et al 2019).…”

Vibrationally resolved photoelectron angular distributions of ammonia

“…Among them, only the band centered at E ≃ 11 eV presents an extended and well-resolved vibrational progression due to the activation of the umbrella inversion mode. 53,58,59 This band is associated to ionization of the 3a 1 HOMO orbital (with an ionization potential of 10.85 eV 51 ), leading to NH 3 + in the electronic ground state, . We focus the present study on the vibrationally resolved photoelectron angular distributions associated with this band for two extreme cases that could be realized under different experimental conditions: perfectly localized and perfectly delocalized initial vibrational states with respect to the umbrella mode coordinate.…”