The rovibrational spectrum of O2–N2O van der Waals complex is measured in the ν1 symmetric stretch region of N2 O monomer using a tunable diode laser spectrometer. The complex is generated by a slit-pulsed supersoni...The rovibrational spectrum of O2–N2O van der Waals complex is measured in the ν1 symmetric stretch region of N2 O monomer using a tunable diode laser spectrometer. The complex is generated by a slit-pulsed supersonic expansion with gas mixtures of O2, N2 O, and He. Both a- and b-type transitions are observed. The effective Hamiltonian for an open-shell complex consisting of a diatomic molecule in a ^3Σ electronic state and a closed-shell partner is used to analyze the observed spectrum. Molecular constants in the vibrationally excited state are determined accurately. The band-origin of the spectrum is determined to be 1284.7504（25） cm^-1, red-shifted from that of the N2 O monomer by ～ 0.1529 cm^-1.展开更多
The assignment of the rovibrational spectra of molecule-Ne complexes is always a challenge to study van der Waals systems, since they usually exhibit behavior intermediate between free rotor and rigid rotor. In this p...The assignment of the rovibrational spectra of molecule-Ne complexes is always a challenge to study van der Waals systems, since they usually exhibit behavior intermediate between free rotor and rigid rotor. In this paper, the microwave and infrared spectra of CH3F-Ne, a model system for symmetric-top-atom dimer, were firstly pre- dicted and analyzed based on the four-dimensional ab initio intermolecular potential energy surfaces（PESs）, which explicitly incorporate the v3（C--F） stretch normal model coordinate of the CH3F monomer. Analytic three-dimensional PESs were obtained by least-squares fitting vibrationally averaged interaction energies for v3（CH3F）=0 and 1 to the Morse/long-range（MLR） potential function for symmetry top impurity with atom model. These PESs fitting to 2340 points have root-mean-square（RMS） deviations of 0.07 cm1, and require only 167 parameters. Based on the analytical vibrationally averaged PESs, the rovibrational energy levels were calculated by employing Lanczos algorithm, with combined radial discrete variable representation and parity-adapted angular finite basis representation. Based on the wavefunction analysis and comparison of CH3F-Ne with CH3F-He and CH3F-Ar complexes, the bound states were assigned. Spectral parameters for CH3F-Rg（Rg： rare gas, Rg=He, Ne, Ar） complexes were fitted and discussed. Temperature dependent transition intensities for CH3F-Ne were also reported and analyzed. The complete microwave and infrared spectra information for CH3F-Ne made it possible to provide important guidance for future experimental spectroscopic assignments.展开更多
基金Project supported by the National Natural Science Foundation of China(Grants Nos.11174098,11304023,and 11304095)
文摘The rovibrational spectrum of O2–N2O van der Waals complex is measured in the ν1 symmetric stretch region of N2 O monomer using a tunable diode laser spectrometer. The complex is generated by a slit-pulsed supersonic expansion with gas mixtures of O2, N2 O, and He. Both a- and b-type transitions are observed. The effective Hamiltonian for an open-shell complex consisting of a diatomic molecule in a ^3Σ electronic state and a closed-shell partner is used to analyze the observed spectrum. Molecular constants in the vibrationally excited state are determined accurately. The band-origin of the spectrum is determined to be 1284.7504（25） cm^-1, red-shifted from that of the N2 O monomer by ～ 0.1529 cm^-1.
基金Supported by the National Natural Science Foundation of China（Nos.21273094, 21533003, 91541124）, the Program for New Century Excellent Talents in University of China（No.NCET-12-0230） and the Project of the Beijing National Laboratory for Molecular Sciences, China（BNLMS）.
文摘The assignment of the rovibrational spectra of molecule-Ne complexes is always a challenge to study van der Waals systems, since they usually exhibit behavior intermediate between free rotor and rigid rotor. In this paper, the microwave and infrared spectra of CH3F-Ne, a model system for symmetric-top-atom dimer, were firstly pre- dicted and analyzed based on the four-dimensional ab initio intermolecular potential energy surfaces（PESs）, which explicitly incorporate the v3（C--F） stretch normal model coordinate of the CH3F monomer. Analytic three-dimensional PESs were obtained by least-squares fitting vibrationally averaged interaction energies for v3（CH3F）=0 and 1 to the Morse/long-range（MLR） potential function for symmetry top impurity with atom model. These PESs fitting to 2340 points have root-mean-square（RMS） deviations of 0.07 cm1, and require only 167 parameters. Based on the analytical vibrationally averaged PESs, the rovibrational energy levels were calculated by employing Lanczos algorithm, with combined radial discrete variable representation and parity-adapted angular finite basis representation. Based on the wavefunction analysis and comparison of CH3F-Ne with CH3F-He and CH3F-Ar complexes, the bound states were assigned. Spectral parameters for CH3F-Rg（Rg： rare gas, Rg=He, Ne, Ar） complexes were fitted and discussed. Temperature dependent transition intensities for CH3F-Ne were also reported and analyzed. The complete microwave and infrared spectra information for CH3F-Ne made it possible to provide important guidance for future experimental spectroscopic assignments.
