Rare isotopic species of hydrogen sulfide: the rotational spectrum of H₂³⁶S

Abstract

The rotational spectrum of the 36 S-bearing isotopologue of hydrogen sulfide (H 2 S) has been investigated for the first time in the 167 GHz−1.6 THz frequency range, thus providing an accurate and reliable set of spectroscopic parameters. The experimental investigation was backed up by state-of-the-art quantum-chemical calculations, which also allowed us to demonstrate the incorrectness of the previously reported spectroscopic constants. The present results are of suitable accuracy to attempt the astrophysical detection of the isotopic species under consideration. Finally, reliable predictions for the spectroscopic constants of other rare isotopologues of H 2 S, namely the mono-and bi-deuterated species containing 33 S and 34 S, are provided.

A twist on the reaction of the CN radical with methylamine in the interstellar medium: new hints from a state-of-the-art quantum-chemical study

“…According to the literature on this topic (see, e.g., Puzzarini et al (2008 (2018)), the rotational constants are expected to have an accuracy, in relative terms, of about 0.1%, while the uncertainties affecting centrifugal-distortion constants and hyperfine parameters should not exceed 1-2%. While these computational results do not have the required accuracy to directly guide astronomical searches, they can surely support laboratory experiments and their analysis (see, e.g., ; Cazzoli et al (2014); Degli Esposti et al (2018)). CH 2 NH 2 and CH 3 NH being radical species, the first challenge for a laboratory investigation is their in situ production.…”

Accuracy of Rotational Parameters Predicted by High-Level Quantum-Chemical Calculations: Case Study of Sulfur-Containing Molecules of Astrochemical Interest

“…Indeed, there is some indication in the literature that the use of a quadruple-zeta basis set is not sufficient. 57,81 As before the discussion is in term of relative errors and the experimental values used as reference [48][49][50][51][52][53][54][55][56][57][58][59][60][61][62][63][82][83][84][85][86][87][88][89][90][91][92][93] are reported in the SI. Table VII: Statistical analysis of the relative errors (in %) in the computed rotational constants with respect to B i e values derived from experimental B i 0 values corrected for vibrational contribution computed at the CCSD(T)/cc-pCVQZ level.…”

Spectroscopic Characterization of Key Aromatic and Heterocyclic Molecules: A Route toward the Origin of Life

“…From the inset, it is evident that the differences can be as small as a few MHz, but also as large as about 100 MHz. Based on the literature on this topic (see, for example, Puzzarini et al 2014b, 2014c; Cazzoli et al 2014), the scaling procedure is able to improve the spectroscopic parameters to such an extent that the rotational transitions can be predicted with an accuracy of 1 MHz or even better. The scaled spectroscopic parameters, based on the data reported in Puzzarini et al 2014a, are collected in Table 1.…”