Simultaneous analysis of rovibrational and rotational data for the 41, 51, 61, 72, 81, 7191 and 92 states of HCOOH

Vibrational spectroscopy of trans and cis deuterated formic acid (HCOOD): Anharmonic calculations and experiments in argon and neon matrices

“…High-resolution measurements of all fundamental, many overtones and combination bands are available (see Ref. [5] and references therein) and an accurate assignment of the rotation-vibration spectral structure has been made with Fermi resonance taken into account [6]. Most of the fundamental bands of trans-HCOOD molecule were also recorded and analyzed in the gas phase [7] and in the matrices although the data for the overtone and combination transitions is sparse.…”

FTIR and millimeter wave investigation of the 71 and 91 states of formic acid HCOOH and H13COOH

“…Therefore, in both cases, all available rotational transitions in the ground state were added to the fit and the ground state parameters were permitted to change. Ground state rotational transitions for HCOOH were those cited in the work dealing with the global analysis of seven higher vibrational states [14]. For H 13 COOH the ground state data reported in [18], from the same FASSST spectrum which was the source of the excited state transitions, were used.…”

“…In the case of the change of rotational quantum numbers the corresponding transition point in the series is marked with a new value of K a . Attribution of the vibrational and rotational quantum numbers to the levels was carried out in accordance with the method described in [14], where first the vibrational state was established and after that the rotational quantum numbers. The very strong mixing of states results in ''forbidden'' transitions in the infrared spectrum and inter-vibrational rotational transitions in the MMW region.…”

“…The MMW and sub-MMW data in the range 115-370 GHz were obtained from a spectrum obtained using the fast scan sub-MMW spectroscopic technique (FASSST) [13,14] recorded for HCOOH with natural abundance. The sample was heated to 170°C and the amplification was adjusted to record weak lines.…”

“…Further details may be found in Ref. [14]. In addition several dozen transitions with an accuracy of 10-20 kHz in the range 86-229 GHz were measured individually in Kharkov.…”