The A^1Π→ X^1Σ^+ transition system of aluminium monochloride is determined by using ab initio quantum chemistry.Based on the multi-reference configuration interaction method in conjugate to the Davidson correction(...The A^1Π→ X^1Σ^+ transition system of aluminium monochloride is determined by using ab initio quantum chemistry.Based on the multi-reference configuration interaction method in conjugate to the Davidson correction(MRCI + Q), the potential energy curves(PECs) of the three electronic states are obtained. Transition dipole moments(TDMs) and the vibrational energy levels are studied by employing the aug-cc-pwCV5Z-DK basis set with 4220-active space. The rovibrational constants are first determined from the analytic potential by solving the rovibrational Schr ¨odinger equation, and then the spectroscopic constants are determined by fitting the vibrational levels, and these values are well consistent with the experimental data. The effect of spin–orbit coupling(SOC) on the spectra and vibrational properties are evaluated.The results show that the SOC effect has almost no influence on the spectroscopic constants of AlCl molecules. For the A^1Π→ X^1Σ^+transition, the highly diagonalized Frank–Condon factor(FCF) is f(00)=0.9988. Additionally, Einstein coefficients and radiative lifetimes are studied, where the vibrational bands include ν''= 0–19→ν'=0–9. The ro-vibrational intensity is calculated at a temperature of 296 K, which can have certain astrophysical applications. At present, there is no report on the calculation of Al Cl ro-vibrational intensity, so we hope that our results will be useful in analyzing the interstellar Al Cl based on the absorption from A^1Π→ X^1Σ^+.展开更多
The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^＋^＋, a^3Π0-, a^3Π0^＋, a^3Π1, a-3Π2, ...The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^＋^＋, a^3Π0-, a^3Π0^＋, a^3Π1, a-3Π2, A-1Π1, 1-3Σ^0^-＋, and 1-3Σ1-＋states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a^3Π0^-, a^3Π0^＋, a^3Π1, and a-3Π2 states, the error from large active space is small. The potential energy curve of the A-1Π1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A-1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a^3Π0^＋）→ X^1Σ0^＋^＋, a-3Π1 → X-1Σ0^＋-＋, and A-1Π1 → X-1Σ0^＋^＋ transitions. Our calculation indicates that the a^3Π1（ ν＇= 0） → X-1Σ0^＋^＋（ν = 0） transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a-3Π1 → X-1Σ0^＋^＋ transitions by using three wavelengths.展开更多
基金Project supported by the National Natural Science Foundation of China(Grant No.61705182)。
文摘The A^1Π→ X^1Σ^+ transition system of aluminium monochloride is determined by using ab initio quantum chemistry.Based on the multi-reference configuration interaction method in conjugate to the Davidson correction(MRCI + Q), the potential energy curves(PECs) of the three electronic states are obtained. Transition dipole moments(TDMs) and the vibrational energy levels are studied by employing the aug-cc-pwCV5Z-DK basis set with 4220-active space. The rovibrational constants are first determined from the analytic potential by solving the rovibrational Schr ¨odinger equation, and then the spectroscopic constants are determined by fitting the vibrational levels, and these values are well consistent with the experimental data. The effect of spin–orbit coupling(SOC) on the spectra and vibrational properties are evaluated.The results show that the SOC effect has almost no influence on the spectroscopic constants of AlCl molecules. For the A^1Π→ X^1Σ^+transition, the highly diagonalized Frank–Condon factor(FCF) is f(00)=0.9988. Additionally, Einstein coefficients and radiative lifetimes are studied, where the vibrational bands include ν''= 0–19→ν'=0–9. The ro-vibrational intensity is calculated at a temperature of 296 K, which can have certain astrophysical applications. At present, there is no report on the calculation of Al Cl ro-vibrational intensity, so we hope that our results will be useful in analyzing the interstellar Al Cl based on the absorption from A^1Π→ X^1Σ^+.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11104217 and 11402199)the Program for New Scientific and Technological Star of Shaanxi Province,China(Grant No.2012KJXX-39)
文摘The feasibility of spin-forbidden cooling of the In H molecule is investigated based on ab initio quantum chemistry calculations. The potential energy curves for the X^1Σ0^＋^＋, a^3Π0-, a^3Π0^＋, a^3Π1, a-3Π2, A-1Π1, 1-3Σ^0^-＋, and 1-3Σ1-＋states of In H are obtained based on multi-reference configuration interaction plus the Davidson corrections method. The calculated spectroscopic constants are in good agreement with the available experimental data. In addition, the influences of the active space and spin–orbit coupling effects on the potential energy curves and spectroscopic constants are also studied. For Re of a^3Π0^-, a^3Π0^＋, a^3Π1, and a-3Π2 states, the error from large active space is small. The potential energy curve of the A-1Π1state is not smooth for small active space. The spin–orbit coupling effects have great influences on the potential well depth and equilibrium internuclear distance of the A-1Π state. The Franck–Condon factors and radiative lifetimes are obtained on the basis of the transition dipole moments of the a^3Π0^＋）→ X^1Σ0^＋^＋, a-3Π1 → X-1Σ0^＋-＋, and A-1Π1 → X-1Σ0^＋^＋ transitions. Our calculation indicates that the a^3Π1（ ν＇= 0） → X-1Σ0^＋^＋（ν = 0） transition provides a highly diagonally distributed Franck–Condon factor and a short radiative lifetime for the a3Π1 state, which can ensure rapid and efficient laser cooling of In H.The proposed laser drives a-3Π1 → X-1Σ0^＋^＋ transitions by using three wavelengths.
