The hyperfine structure in the rotational spectra of D2O: Lamb-dip measurements and quantum-chemical calculations

Rotational spectroscopy for astrophysical investigations

“…The investigation reported in Cazzoli et al (2010) is a significant example that this requirement can be largely fulfilled. In Cazzoli et al (2010), the rotational spectrum of trans-formic acid was investigated: the Lamb-dip technique was exploited in order to record the rotational spectrum at sub-Doppler resolution in the millimeter-and submillimeter-wave frequency ranges (80-600 GHz) and to resolve the hyperfine structure due to the hydrogen nuclei, while Doppler-limited measurements were carried out in the 1.0-1.6 THz frequency range. Rend.…”

“…The relevance of this combined approach is well documented and there is an ever-growing number of papers dealing with this topic (see, for example Cazzoli et al 2010;Carvajal et al 2010). …”

Hyperfine structure in the rotational spectra of trans-formic acid: Lamb-dip measurements and quantum-chemical calculations

“…From our previous work (see, for example, Cazzoli et al 2009;Puzzarini et al 2009;Cazzoli et al 2010), we already know that the CCSD(T) method employed in conjunction with a corevalence basis set of at least quadruple-zeta quality is suitable for obtaining equilibrium values for quantitative predictions, while a triple-zeta quality basis is usually sufficient to provide accurate vibrational corrections. Including vibrational corrections is mandatory for obtaining quantitative agreement with experiment.…”

Precise Laboratory Measurements of Trans-Dcooh and Trans-Hcood for Astrophysical Observations

“…This is evident from the given error estimate but also from a comparison with the theoretically predicted value for C aa . The latter and all the other values should be considered rather reliable, as based on our previous experience (see for example, Puzzarini et al 2010;Cazzoli et al 2009Cazzoli et al , 2010aCazzoli et al , 2010bCazzoli et al , 2011 almost quantitative estimates can be obtained from CCSD(T) calculations using large basis sets (quintuple-or sextuple-zeta sets) corrected for vibrational effects. The inclusion of the latter is essential for reaching high accuracy, as in the present case they amount to 6%-10% for deuterium quadrupole coupling and hydrogen spin-rotation tensors and thus are far from negligible.…”