Collisions of cold and ultracold BH in the v= 0 level with the He atom are investigated using the quantum mechanical scattering formulation. The elastic and the inelastic cross sections are calculated using the two-di...Collisions of cold and ultracold BH in the v= 0 level with the He atom are investigated using the quantum mechanical scattering formulation. The elastic and the inelastic cross sections are calculated using the two-dimensional ab initio potential energy surface. It is shown that the elastic cross section is larger than the inelastic one. When the collision energy is very low, the elastic cross section follows the Wigner threshold law and is one order of magnitude larger than that of He-O2, while it is much smaller than that of He--H2. The efficiency of the rotationally quenching state is given. The △j = -1 transition is most efficient. The resonances are also found to occur at about the same translational energy （0.1-1 cm-1）, which gives rise to steps in the rate coefficient at temperatures around 0.1-1 K.展开更多
The interaction potential of a He-BH complex is investigated by the coupled-cluster single-double plus perturbative triples （CCSD （T）） method and an augmented correlation consistent polarized valence （aug-cc-pV）...The interaction potential of a He-BH complex is investigated by the coupled-cluster single-double plus perturbative triples （CCSD （T）） method and an augmented correlation consistent polarized valence （aug-cc-pV）5Z basis set extended with a set of （3s3p2dlflg） midbond functions. Using the five two-dimensional model potentials, the first three-dimensional interaction potential energy surface is constructed by interpolating along （r-re） by using a fourth-order polynomial. The cross sections for the rovibrational relaxation of BH in cold and ultracold collisions with 3He atom are calculated based on the three-dimensional potential. The results show that the △v =-1 transition is more efficient than the △v=-2 transition, and that the process of relaxation takes place mainly between rotational energy levels with the same vibration state and the △j=-1 transition is the most efficient. The zero temperature quenching rate coefficient is finite as predicted by Wigner＇s law. The resonance is found to take place around 0.1-1 cm^-1 translational energy, which gives rise to a step in the rate coefficients for temperatures around 0.1-1 K. The final rotational distributions in the state v = 0 resulting from the quenching of state （v = 1,j = 0） at three energies corresponding to the three different regimes are also given.展开更多
基金supported by the National Natural Science Foundation of China(Grant No.10874001)the Key Grant Project of Chinese Ministry of Education(Grant No.208057)+1 种基金the Natural Science Foundation of Anhui Province,China(Grant Nos.070416236 and KJ2010B366)the Natural Science Foundation of Anhui Normal University,China(Grant No.160-720857)
文摘Collisions of cold and ultracold BH in the v= 0 level with the He atom are investigated using the quantum mechanical scattering formulation. The elastic and the inelastic cross sections are calculated using the two-dimensional ab initio potential energy surface. It is shown that the elastic cross section is larger than the inelastic one. When the collision energy is very low, the elastic cross section follows the Wigner threshold law and is one order of magnitude larger than that of He-O2, while it is much smaller than that of He--H2. The efficiency of the rotationally quenching state is given. The △j = -1 transition is most efficient. The resonances are also found to occur at about the same translational energy （0.1-1 cm-1）, which gives rise to steps in the rate coefficient at temperatures around 0.1-1 K.
基金Project supported by the National Natural Science Foundation of China (Grant No. 10874001)the Key Grant Project of the Chinese Ministry of Education (Grant No. 208057)the Natural Science Foundation of Anhui Province, China (Grant No. 070416236)
文摘The interaction potential of a He-BH complex is investigated by the coupled-cluster single-double plus perturbative triples （CCSD （T）） method and an augmented correlation consistent polarized valence （aug-cc-pV）5Z basis set extended with a set of （3s3p2dlflg） midbond functions. Using the five two-dimensional model potentials, the first three-dimensional interaction potential energy surface is constructed by interpolating along （r-re） by using a fourth-order polynomial. The cross sections for the rovibrational relaxation of BH in cold and ultracold collisions with 3He atom are calculated based on the three-dimensional potential. The results show that the △v =-1 transition is more efficient than the △v=-2 transition, and that the process of relaxation takes place mainly between rotational energy levels with the same vibration state and the △j=-1 transition is the most efficient. The zero temperature quenching rate coefficient is finite as predicted by Wigner＇s law. The resonance is found to take place around 0.1-1 cm^-1 translational energy, which gives rise to a step in the rate coefficients for temperatures around 0.1-1 K. The final rotational distributions in the state v = 0 resulting from the quenching of state （v = 1,j = 0） at three energies corresponding to the three different regimes are also given.
