Showing papers by "Cristina Puzzarini published in 2007"

Experimental and theoretical investigation on pressure-broadening and pressure-shifting of the 22.2 GHz line of water

Abstract: Since water is a fundamental component of the atmosphere and it is well established that the accuracy of collisional broadening parameters has a crucial influence on reduction of remote sensing data, we decided to investigate the self-, N 2 - and O 2 -broadening parameters of the J = 6 1 , 6 ← 5 2 , 3 (22.2 GHz) rotational transition of water in the temperature range 296–338 K. Due to the relevance of this water line, this investigation should be considered of particular interest in monitoring the Earth's atmosphere, and therefore a particular effort has been made in order to reduce instrumental as well as systematic errors. Experimental determinations have also been supported by theoretical calculations.

Rotational spectra of rare isotopic species of bromofluoromethane: determination of the equilibrium structure from ab initio calculations and microwave spectroscopy.

Abstract: Guided by theoretical predictions, the rotational spectra of the mono- and bideuterated species of bromofluoromethane, CDHBr79F, CDHBr81F, CD2Br79F, and CD2Br81F, have been recorded for the first time. Assignment of a few hundred rotational transitions led to the accurate determination of the ground-state rotational constants, all of the quartic and most of the sextic centrifugal distortion constants, as well as the full bromine quadrupole-coupling tensor for both Br79 and Br81, in good agreement with corresponding theoretical predictions based on high-level coupled-cluster calculations. The rotational spectra of the C13 containing species C13H2Br79F and C13H2Br81F have been observed in natural abundance and have been assigned, thus allowing the determination of the rotational and centrifugal distortion constants as well as the bromine quadrupole-coupling tensor. Furthermore, empirical equilibrium structures have been obtained within a least-squares fit procedure using the available experimental ground-st...

High-Resolution FTIR, Microwave, and Ab Initio Investigations of CH279BrF: Ground, v5 = 1, and v6 = 1, 2 State Constants

Abstract: A spectroscopic study of CH279BrF in the infrared and microwave regions has been carried out. The rovibrational spectrum of the ν5 fundamental interacting with 2ν6 has been investigated by high-resolution FTIR spectroscopy. Owing to the weakness of the 2ν6 band, the v6 = 2 state constants have been derived from v6 = 1. For this reason, the rotational spectra of the ground and v6 = 1 states have been observed by means of microwave spectroscopy. Highly accurate ab initio computations have also been performed at the CCSD(T) level of theory in order to support the experimental investigation. As far as the ν5 band is concerned, the analysis of the rovibrational structure led to the identification of more than 3000 transitions, allowing the determination of a set of spectroscopic parameters up to sextic distortion terms and pointing out first-order c-type Coriolis interaction with the v6 = 2 state. With regard to the pure rotational spectra measurements, the assignment of several ΔJ = 0, +1 transitions allowed ...