The Condon locus for a diatomic molecule is the locus, in the plane, of the strongest bands in an electronic band system. The form of the locus depends upon the form of the potential energy function of the electronic ...The Condon locus for a diatomic molecule is the locus, in the plane, of the strongest bands in an electronic band system. The form of the locus depends upon the form of the potential energy function of the electronic states involved. We show how the locus depends on the potential energy function for simple harmonic and anharmonic oscillators, first from a classical point of view, and then from a quantum mechanical point of view. One phenomenon of interest is that, in the case of anharmonic oscillators, the upper branch of the Condon locus traces much stronger bands than the lower branch. Another phenomenon, predicted by quantum mechanics but not by classical mechanics, is the existence of secondary nested Condon loci.展开更多
The feasibility of laser cooling a CH molecule is investigated theoretically by employing the ab initio method. The potential energy curves for the five ∧-S states and eight Ω states of CH are determined by the mult...The feasibility of laser cooling a CH molecule is investigated theoretically by employing the ab initio method. The potential energy curves for the five ∧-S states and eight Ω states of CH are determined by the multi-reference configuration interaction with the Davidson corrections（MRCI＋Q） level of theory. The results agree well with the available experimental data and other theoretical values. Also, the permanent dipole moments and transition dipole moments of the CH molecule are calculated at the multi-reference configuration interaction（MRCI） level. We find highly diagonally distributed FranckCondon factors（f00 = 0.9950 and 0.9998） and branching ratios（R00 = 0.983 and 0.993） for the A^2△→ X2Π and C^2∑^＋→X^2Π transitions. Moreover, the values of suitable radiative lifetime τ of the A2 A and C^2∑^＋ states are evaluated to be9.64×10^-7 s and 2.02×10^-7 s, respectively, for rapid laser cooling. A scheme for laser cooling the CH molecule is designed. In the proposed cooling scheme, three wavelengths for A^2△→X^2Π and C^2∑^＋→X^2Π transitions are used, and the main pump lasers are λ00=430.86 nm and 313.45 nm, respectively. The feasibility of laser cooling the CH molecules is demonstrated for each of these schemes, and this study offers a theoretical basis for experimental research into preparation of cold CH molecules.展开更多
An ab initio calculations on the ground and low-lying excited statesX2∑＋,2^2∑＋,3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋,and 3^4∑＋of KBe molecule have been performed using multireference configuration interaction （M...An ab initio calculations on the ground and low-lying excited statesX2∑＋,2^2∑＋,3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋,and 3^4∑＋of KBe molecule have been performed using multireference configuration interaction （MRCI） plus Davidsoncorrections （MRCI＋Q） approach with all electron basis set aug-cc-pCV5Z-DK for Be and def2-AQZVPP-JKFI for K.3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋and3^4∑＋states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves （PECs） calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck-Condon factors qv′v″, Einstein coefficients Av′v″, and the radiative lifetimesτ′for the2^2∑＋-X2∑＋,3^2∑＋-X2∑＋,and 2^4∏-1^4∏ transitions are predictedat the same time.展开更多
Potential energy curves of the X^(1)Σ+and A;Πstates of the Al F molecule are studied through the combination of the multi-reference configuration interaction(MRCI)approach and Davidson corrections(MRCI+Q).The AWCV5 ...Potential energy curves of the X^(1)Σ+and A;Πstates of the Al F molecule are studied through the combination of the multi-reference configuration interaction(MRCI)approach and Davidson corrections(MRCI+Q).The AWCV5 Z basis set is employed in the calculations.The transition dipole moments(TDMs)of the A;Π■X^(1)Σ+transition are explored based on the AWCV5 Z basis set and(4,2,2,0)active space.The Schrödinger equation is solved via the LEVEL 8.2 program,and the vibrational levels and rotational constants of the X^(1)Σ+and A1Πstates are calculated.It is shown that the Al F molecule has high diagonal Franck-Condon factors(f00=0.9949 and f11=0.9854)and large Einstein coefficients for the transition of A;Π(ν′=0)■X^(1)Σ+(ν′′=0).In addition,the radiative lifetimes of the vibrational levels are close to 10-9 s for the A;Πstate.The line intensities of the A;Π(ν′=4-15)■X^(1)Σ+(ν′′=0)transitions are also calculated.The calculated TDMs and transition probabilities in this work are credible and provide some guidance for the study of similar transitions,particularly for exploring interstellar space.展开更多
PbF,a valuable candidate for measuring the electron electric dipole moment(eEDM),is of great significance in measuring its spectrum and deriving its molecular constants in experiment.In the present work,the rovibronic...PbF,a valuable candidate for measuring the electron electric dipole moment(eEDM),is of great significance in measuring its spectrum and deriving its molecular constants in experiment.In the present work,the rovibronic spectrum of the B^(2)Σ^(+)-X_(1)^(2)Π_(1/2) transition of PbF in a wavelength range of 260 nm-285 nm is studied by the laser ablation/laser induced fluorescence method.The molecular parameters of the X_(1)^(2)Π_(1/2)(v"=0)and B^(2)Σ+(v'=0,1)states are derived from the recorded spectra of the(0,0)and(1,0)bands of the B^(2)Σ+-X_(1)^(2)Π_(1/2) transition.Also,the Franck-Condon factors(FCFs)of the transitions between the B^(2)Σ+and X_(1)^(2)Π_(1/2)states are calculated by the RKR/LEVEL method and the Morse potential method,respectively.展开更多
We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2...We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2∑＋（v＂=0,1） system by analyzing the experimental spectrum. Also, we calculate the Franck-Condon factors and transition frequencies of the A2H-X2∑＋ system of MgH. A comparison of our theoretical calculation and experimental results with other reported theoretical results was carried out as well.展开更多
文摘The Condon locus for a diatomic molecule is the locus, in the plane, of the strongest bands in an electronic band system. The form of the locus depends upon the form of the potential energy function of the electronic states involved. We show how the locus depends on the potential energy function for simple harmonic and anharmonic oscillators, first from a classical point of view, and then from a quantum mechanical point of view. One phenomenon of interest is that, in the case of anharmonic oscillators, the upper branch of the Condon locus traces much stronger bands than the lower branch. Another phenomenon, predicted by quantum mechanics but not by classical mechanics, is the existence of secondary nested Condon loci.
基金Project supported by the National Natural Science Foundation of China(Grant No.61705182)
文摘The feasibility of laser cooling a CH molecule is investigated theoretically by employing the ab initio method. The potential energy curves for the five ∧-S states and eight Ω states of CH are determined by the multi-reference configuration interaction with the Davidson corrections（MRCI＋Q） level of theory. The results agree well with the available experimental data and other theoretical values. Also, the permanent dipole moments and transition dipole moments of the CH molecule are calculated at the multi-reference configuration interaction（MRCI） level. We find highly diagonally distributed FranckCondon factors（f00 = 0.9950 and 0.9998） and branching ratios（R00 = 0.983 and 0.993） for the A^2△→ X2Π and C^2∑^＋→X^2Π transitions. Moreover, the values of suitable radiative lifetime τ of the A2 A and C^2∑^＋ states are evaluated to be9.64×10^-7 s and 2.02×10^-7 s, respectively, for rapid laser cooling. A scheme for laser cooling the CH molecule is designed. In the proposed cooling scheme, three wavelengths for A^2△→X^2Π and C^2∑^＋→X^2Π transitions are used, and the main pump lasers are λ00=430.86 nm and 313.45 nm, respectively. The feasibility of laser cooling the CH molecules is demonstrated for each of these schemes, and this study offers a theoretical basis for experimental research into preparation of cold CH molecules.
基金Project supported by the National Natural Science Foundation of China(Grant No.11647075)the Scientific Research Fund of Sichuan Provincial Education Department,China(Grant No.14ZB0284)the Scientific Research Key Project of Yibin University,China(Grant No.2013QD09)
文摘An ab initio calculations on the ground and low-lying excited statesX2∑＋,2^2∑＋,3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋,and 3^4∑＋of KBe molecule have been performed using multireference configuration interaction （MRCI） plus Davidsoncorrections （MRCI＋Q） approach with all electron basis set aug-cc-pCV5Z-DK for Be and def2-AQZVPP-JKFI for K.3^2∑＋,1^4∏,2^4∏,1^4∑＋,2^4∑＋and3^4∑＋states are investigated for the first time. Inner shell electron correlations are computed on the potential energy curves （PECs） calculations. The spectroscopic and molecular parameters are also predicted. In addition, The transition properties including transition dipole moment, Franck-Condon factors qv′v″, Einstein coefficients Av′v″, and the radiative lifetimesτ′for the2^2∑＋-X2∑＋,3^2∑＋-X2∑＋,and 2^4∏-1^4∏ transitions are predictedat the same time.
基金supported by the National Natural Science Foundation of China(Grant No.11947127)the Shaanxi Natural Science Foundation,China(Grant No.2018JM1053)。
文摘Potential energy curves of the X^(1)Σ+and A;Πstates of the Al F molecule are studied through the combination of the multi-reference configuration interaction(MRCI)approach and Davidson corrections(MRCI+Q).The AWCV5 Z basis set is employed in the calculations.The transition dipole moments(TDMs)of the A;Π■X^(1)Σ+transition are explored based on the AWCV5 Z basis set and(4,2,2,0)active space.The Schrödinger equation is solved via the LEVEL 8.2 program,and the vibrational levels and rotational constants of the X^(1)Σ+and A1Πstates are calculated.It is shown that the Al F molecule has high diagonal Franck-Condon factors(f00=0.9949 and f11=0.9854)and large Einstein coefficients for the transition of A;Π(ν′=0)■X^(1)Σ+(ν′′=0).In addition,the radiative lifetimes of the vibrational levels are close to 10-9 s for the A;Πstate.The line intensities of the A;Π(ν′=4-15)■X^(1)Σ+(ν′′=0)transitions are also calculated.The calculated TDMs and transition probabilities in this work are credible and provide some guidance for the study of similar transitions,particularly for exploring interstellar space.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11674096 and 11874151).
文摘PbF,a valuable candidate for measuring the electron electric dipole moment(eEDM),is of great significance in measuring its spectrum and deriving its molecular constants in experiment.In the present work,the rovibronic spectrum of the B^(2)Σ^(+)-X_(1)^(2)Π_(1/2) transition of PbF in a wavelength range of 260 nm-285 nm is studied by the laser ablation/laser induced fluorescence method.The molecular parameters of the X_(1)^(2)Π_(1/2)(v"=0)and B^(2)Σ+(v'=0,1)states are derived from the recorded spectra of the(0,0)and(1,0)bands of the B^(2)Σ+-X_(1)^(2)Π_(1/2) transition.Also,the Franck-Condon factors(FCFs)of the transitions between the B^(2)Σ+and X_(1)^(2)Π_(1/2)states are calculated by the RKR/LEVEL method and the Morse potential method,respectively.
基金This work was supported by the National Nature Science Foundation of China （No.61205198, No.11105052） and the Fundamental Research Fhnds for the Central Universities. The authors thank Chao Hang from State Key Laboratory of Precision Spectroscopy, East China Normal University and Timothy Steimles from Chemistry and Biochemistry Department, Arizona State University for the discussion.
文摘We measure the dispersed spectrum of the A2H-X2E＋ system of MgH using laser abla- tion/laser induced Fluorescence method and obtain the Frank-Condon factors and related transition frequencies of the A2H（v＇=0）-X2∑＋（v＂=0,1） system by analyzing the experimental spectrum. Also, we calculate the Franck-Condon factors and transition frequencies of the A2H-X2∑＋ system of MgH. A comparison of our theoretical calculation and experimental results with other reported theoretical results was carried out as well.
