To get a mole of a gas, it is necessary to calculate the intermolecular interaction. Theseintermolecular interactions can be depicted by drawing the potential energy of a pair molecule inrelation to the distance. The intermolecular potential energy surface in the mixtures of CH4-H2COgases from ab initio calculations has been explored. In ab initio calculations the basis setsuperposition error (...

to get a mole of a gas, it is necessary to calculate the intermolecular interaction. theseintermolecular interactions can be depicted by drawing the potential energy of a pair molecule inrelation to the distance. the intermolecular potential energy surface in the mixtures of ch4-h2cogases from ab initio calculations has been explored. in ab initio calculations the basis setsuperposition error (...

High angular resolution H2CO line observations have been carried out for the low mass proto-binary star IRAS 16293–2422 using the OVROmillimeter array. Simultaneous continuum observations reveal that the source most probably contains two accretion disks, less than ∼ 250AU in size, through which matter is fed onto the stars. The observations suggest that the binary has cleared most of the materi...

High angular resolution H2CO 218 GHz line observations have been carried out toward the low-mass protostars IRAS 16293–2422 and L1448–C using the Owens Valley Millimeter Array at ∼2′′ resolution. Simultaneous 1.37 mm continuum data reveal extended emission which is compared with that predicted by model envelopes constrained from single-dish data. For L1448–C the model density structure works we...

We present Submillimeter Array observations of H2CO and N2H + emission in the disks around the T Tauri star TW Hya and the Herbig Ae star HD 163296 at 2–6 resolution and discuss the distribution of these species with respect to CO freeze-out. The H2CO and N2H + emission toward HD 163296 does not peak at the continuum emission center that marks the stellar position but is instead significantly o...

The development of an interband cascade laser (ICL) based spectroscopic trace-gas sensor for the simultaneous detection of two atmospheric trace gases is reported. The sensor performance was evaluated using two ICLs capable of targeting formaldehyde (H2CO) and ethane (C2H6). Minimum detection limits of 3.5 ppbV for H2CO and 150 pptV for C2H6 was demonstrated with a 1 s integration time. The sen...

Using the VLA and NRAO 140′ telescopes we observed the λ1.3 cm (1, 1) and (2, 2) lines of NH3 in absorption and emission toward the compact extragalactic continuum sources NRAO150 (B0355+508) and 3C 111 (B0415+379). These sources are occulted by some seven local diffuse and translucent clouds showing molecular absorption in OH, CO, HCO and C2H: for the four features having NH3 absorption, we fi...

We report the detection of H2CO (formaldehyde) around the carbon-rich AGB star, IRC+10216. We find a fractional abundance with respect to molecular hydrogen of x(H2CO) = 1.3 +1.5 −0.8 × 10 . This corresponds to a formaldehyde abundance with respect to water vapor of x(H2CO)/x(H2O) = (1.1±0.2)×10 , in line with the formaldehyde abundances found in Solar System comets, and indicates that the puta...

The frequencies and intensities for the vibrational bands of absorption spectra hydrogen-bonded (D2CO)2 D2CO∙∙∙DF dimers, two D2CO∙∙∙(DF)2 trimers four (D2CO)2∙∙∙DF are calculated in MP2/aug-cc-pVTZ approximation with basis set superposition error taken into account. Anharmonic values spectral parameters were obtained using second-order perturbation theory. influence hydrogen bonds on was deter...

We report the results of our third survey for formaldehyde (H2CO) 6 cm maser emission in the Galaxy. Using the Very Large Array, we detected two new H2CO maser sources (G23.01−0.41 and G25.83−0.18), thus increasing the sample of known H2CO maser regions in the Galaxy to seven. We review the characteristics of the G23.01−0.41 and G25.83−0.18 star forming regions. The H2CO masers in G23.01−0.41 a...