Based on a high level ab initio calculation which is earned out with the multireference configuration interaction method under the aug-cc-pVXZ(AVXZ)basis sets,X=T,Q,5,the accurate potential energy curves(PECs)of the g...Based on a high level ab initio calculation which is earned out with the multireference configuration interaction method under the aug-cc-pVXZ(AVXZ)basis sets,X=T,Q,5,the accurate potential energy curves(PECs)of the ground state X^(1)Σ_(g)^(+)and the first excited state A^(1)Σ_(u)^(+)of Li_(2)are constructed.By fitting the ab initio potential energy points with the MurrellSorbie potential function,the analytic potential energy functions(APEFs)are obtained.The molecular bond length at the equilibnum(R_(e)),the potential well depth(D_(e)),and the spectroscopic constants(B_(e),ω_(e),α_(e),andω_(e)χ_(e))for the X^(1)Σ_(g)^(+)state and the A^(1)Σ_(u)^(+)state are deduced from the APEFs.The vibrational energy levels of the two electronic states are obtained by solving the time-independent Schrodmger equation with the Founer gnd Hamiltonian method.All the spectroscopic constants and the vibrational levels agree well with the experimental results.The Franck-Condon factors(FCFs)corresponding to the transitions from the vibrational level(v’=0)of the ground state to the vibrational levels(v"=0-74)of the first excited state have been calculated.The FCF for the vibronic transition of A^(1)Σ_(u)^(+)(v"=0)←X^(1)Σ_(g)^(+)(v’=0)is the strongest.These PECs and corresponding spectroscopic constants provide reliable theoretical references to both the spectroscopic and the molecular dynamic studies of the Li_(2)dimer.展开更多
基金supported by the National Key R&D Program of China No.2018YFA0306503the National Natural Science Foundation of China under Grant Nos.21873016,12174044+1 种基金the International Cooperation Fund Project of DBJI No.ICR2105the Fundamental Research Funds for the Central Universities(DUT21LK08)。
文摘Based on a high level ab initio calculation which is earned out with the multireference configuration interaction method under the aug-cc-pVXZ(AVXZ)basis sets,X=T,Q,5,the accurate potential energy curves(PECs)of the ground state X^(1)Σ_(g)^(+)and the first excited state A^(1)Σ_(u)^(+)of Li_(2)are constructed.By fitting the ab initio potential energy points with the MurrellSorbie potential function,the analytic potential energy functions(APEFs)are obtained.The molecular bond length at the equilibnum(R_(e)),the potential well depth(D_(e)),and the spectroscopic constants(B_(e),ω_(e),α_(e),andω_(e)χ_(e))for the X^(1)Σ_(g)^(+)state and the A^(1)Σ_(u)^(+)state are deduced from the APEFs.The vibrational energy levels of the two electronic states are obtained by solving the time-independent Schrodmger equation with the Founer gnd Hamiltonian method.All the spectroscopic constants and the vibrational levels agree well with the experimental results.The Franck-Condon factors(FCFs)corresponding to the transitions from the vibrational level(v’=0)of the ground state to the vibrational levels(v"=0-74)of the first excited state have been calculated.The FCF for the vibronic transition of A^(1)Σ_(u)^(+)(v"=0)←X^(1)Σ_(g)^(+)(v’=0)is the strongest.These PECs and corresponding spectroscopic constants provide reliable theoretical references to both the spectroscopic and the molecular dynamic studies of the Li_(2)dimer.
