The high accuracy ab initio calculation method of multi-reference configuration interaction（MRCI） is used to compute the low-lying eight electronic states of CuN.The potential energy curves（PECs） of the X;∑;,1;Π...The high accuracy ab initio calculation method of multi-reference configuration interaction（MRCI） is used to compute the low-lying eight electronic states of CuN.The potential energy curves（PECs） of the X;∑;,1;Π,2;∑;,1;△,1;△,1;∑;,1;Π,and;∑;in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu（;S;） + N（;S;） and Cu（;S;）+N（;D;） dissociation limits.All the possible vibrational levels,rotational constants,and spectral constants for the six bound states of X;∑;,1;Π,2;∑;,1;△,1;∑;,and 1;Π are obtained by solving the radial Schrdinger equation of nuclear motion with the Le Roy provided Level 8.0 program.Also the transition dipole moments from the ground state X;∑;to the excited states 1;Π and 2;∑;are calculated and the result indicates that the 2;∑-X;∑ transition has a much higher transition dipole moment than the 1;Π-X;∑;transition even though the l;Π state is much lower in energy than the 2;∑;state.展开更多
本文采用完全活性空间自洽场(complete active space self-consistent field,CASSCF)和加戴维森校正的多参考组态相互作用(multireference configuration interaction with Davidson correction,MRCI+Q)方法,研究了超氧阴离子(O_(2)^(-)...本文采用完全活性空间自洽场(complete active space self-consistent field,CASSCF)和加戴维森校正的多参考组态相互作用(multireference configuration interaction with Davidson correction,MRCI+Q)方法,研究了超氧阴离子(O_(2)^(-))的低激发电子态及自旋-轨道耦合(spin-orbit coupling,SOC)效应对电子态的影响.使用aug-cc-pV5Z-dk基组,计算了O_(2)^(-)第一和第二解离极限对应的42个Λ-S态的势能曲线(potential energy curves,PECs)以及束缚态的光谱常数.同时考虑SOC效应,计算了这42个Λ-S态分裂形成的84个Ω态的PECs和部分束缚态的光谱常数.其中第一解离极限结果与已有文献高度一致,第二解离极限结果为本文计算提供.这些结果为研究O_(2)^(-)的电子结构和光谱性质提供了重要的理论依据.针对a^(4)Σ_(4)^(-)态的双势阱现象,本文通过比较不同基组下的计算结果,证实了a^(4)Σ_(4)^(-)态的双势阱形成源于与a^(4)Σ_(4)^(-)态的避免交叉影响.此外,研究发现基组大小直接影响a^(4)Σ_(4)^(-)态的首个势阱深度,这进一步表明基组选择对光谱常数计算的精确性至关重要.本文数据集可在科学数据银行https://doi.org/10.57760/sciencedb.j00213.00076中访问获取.展开更多
The spectroscopic and transition properties of strontium chloride(SrCl)are investigated based on the theoretical approach of ab initio quantum chemistry.The calculation accuracy is improved by introducing Davidson cor...The spectroscopic and transition properties of strontium chloride(SrCl)are investigated based on the theoretical approach of ab initio quantum chemistry.The calculation accuracy is improved by introducing Davidson correction,core-valence correlation(CV),the scalar relativistic and spin–orbit coupling(SOC)effects.The results show that the spectroscopic constants of X^(2)S^(+)and A^(2)∏states are consistent with the experimental results.The spectroscopic and molecular constants of most highly excited electronic states are reported for the first time.The permanent dipole moment(PDMs)and the spin–orbit(SO)matrix element have a sudden change for the avoidance of crossing.The potential energy curves(PECs)of the 14 L–S states split into 30Ωstates.The splitting energy of A^(2)∏is 290.76 cm^(-1),which has a little difference from the experimental value 295.597 cm^(-1).Finally,the transition properties are given,including transition dipole moment(TDMs),Franck–Canton factor(FCFs)and radiation lifetime.It is found that the calculated radiation lifetime is in the order of 10 ns.The research will provide a theoretical reference for the feasibility of laser cooling of SrCl molecule.The dataset that supported the findings of this study is available in Science Data Bank,with the link https://www.doi.org/10.57760/sciencedb.j00113.00218.展开更多
The potential energy curves （PECs） of BO molecule, including ∑^＋and ∏ symmetries with doublet spin multiplicities, are obtained employing multi-reference configuration interaction （MRCI） method and Dunning＇s c...The potential energy curves （PECs） of BO molecule, including ∑^＋and ∏ symmetries with doublet spin multiplicities, are obtained employing multi-reference configuration interaction （MRCI） method and Dunning＇s correlation consistent basis sets. The analytical potential energy functions （APEFs） are fitted using the Murrell-Sorbie （MS） function and the least square method. Based on the PECs, the spectroscopic constants of the states have been determined and compared with the theoretical and experimental results available to affirm the accuracy and liability of the calculations. The root-mean-square （RMS） errors between the fitted results and the ab initio values are too little in comparison with the chemical accuracy （349.755 cm^-1）. It is shown that the present APEFs are accurate and can display the interaction between the atoms well. The present APEFs can be used to construct more complicated APEF or do some dynamic investigations.展开更多
The potential energy curves for the X1 SUM_g^+,B1 DELTA_g and B'1 SUM_g^+states of C2 have been studied by using MRCl and approximate Cl methods,and are benchmarked againstthe calculations of full configuration in...The potential energy curves for the X1 SUM_g^+,B1 DELTA_g and B'1 SUM_g^+states of C2 have been studied by using MRCl and approximate Cl methods,and are benchmarked againstthe calculations of full configuration interaction (FCl).The results obtained by MRCl method agreewith the FCl very well,and even are accurate enough to compare other approximate methods asbenchmark,when the calculations of FCI are not feasible.The approximate Cl methods mentioned in thispaper are reliable for treating chemical problems.展开更多
文摘The high accuracy ab initio calculation method of multi-reference configuration interaction（MRCI） is used to compute the low-lying eight electronic states of CuN.The potential energy curves（PECs） of the X;∑;,1;Π,2;∑;,1;△,1;△,1;∑;,1;Π,and;∑;in a range of R=0.1 nm-0.5 nm are obtained and they are goodly asymptotes to the Cu（;S;） + N（;S;） and Cu（;S;）+N（;D;） dissociation limits.All the possible vibrational levels,rotational constants,and spectral constants for the six bound states of X;∑;,1;Π,2;∑;,1;△,1;∑;,and 1;Π are obtained by solving the radial Schrdinger equation of nuclear motion with the Le Roy provided Level 8.0 program.Also the transition dipole moments from the ground state X;∑;to the excited states 1;Π and 2;∑;are calculated and the result indicates that the 2;∑-X;∑ transition has a much higher transition dipole moment than the 1;Π-X;∑;transition even though the l;Π state is much lower in energy than the 2;∑;state.
文摘本文采用完全活性空间自洽场(complete active space self-consistent field,CASSCF)和加戴维森校正的多参考组态相互作用(multireference configuration interaction with Davidson correction,MRCI+Q)方法,研究了超氧阴离子(O_(2)^(-))的低激发电子态及自旋-轨道耦合(spin-orbit coupling,SOC)效应对电子态的影响.使用aug-cc-pV5Z-dk基组,计算了O_(2)^(-)第一和第二解离极限对应的42个Λ-S态的势能曲线(potential energy curves,PECs)以及束缚态的光谱常数.同时考虑SOC效应,计算了这42个Λ-S态分裂形成的84个Ω态的PECs和部分束缚态的光谱常数.其中第一解离极限结果与已有文献高度一致,第二解离极限结果为本文计算提供.这些结果为研究O_(2)^(-)的电子结构和光谱性质提供了重要的理论依据.针对a^(4)Σ_(4)^(-)态的双势阱现象,本文通过比较不同基组下的计算结果,证实了a^(4)Σ_(4)^(-)态的双势阱形成源于与a^(4)Σ_(4)^(-)态的避免交叉影响.此外,研究发现基组大小直接影响a^(4)Σ_(4)^(-)态的首个势阱深度,这进一步表明基组选择对光谱常数计算的精确性至关重要.本文数据集可在科学数据银行https://doi.org/10.57760/sciencedb.j00213.00076中访问获取.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11564019,11147158,and 12464032)the Department of Education Foundation of Jiangxi Province of China(Grant No.GJJ2401520).
文摘The spectroscopic and transition properties of strontium chloride(SrCl)are investigated based on the theoretical approach of ab initio quantum chemistry.The calculation accuracy is improved by introducing Davidson correction,core-valence correlation(CV),the scalar relativistic and spin–orbit coupling(SOC)effects.The results show that the spectroscopic constants of X^(2)S^(+)and A^(2)∏states are consistent with the experimental results.The spectroscopic and molecular constants of most highly excited electronic states are reported for the first time.The permanent dipole moment(PDMs)and the spin–orbit(SO)matrix element have a sudden change for the avoidance of crossing.The potential energy curves(PECs)of the 14 L–S states split into 30Ωstates.The splitting energy of A^(2)∏is 290.76 cm^(-1),which has a little difference from the experimental value 295.597 cm^(-1).Finally,the transition properties are given,including transition dipole moment(TDMs),Franck–Canton factor(FCFs)and radiation lifetime.It is found that the calculated radiation lifetime is in the order of 10 ns.The research will provide a theoretical reference for the feasibility of laser cooling of SrCl molecule.The dataset that supported the findings of this study is available in Science Data Bank,with the link https://www.doi.org/10.57760/sciencedb.j00113.00218.
基金supported by the National Natural Science Foundation of China under Grant No. 10674114
文摘The potential energy curves （PECs） of BO molecule, including ∑^＋and ∏ symmetries with doublet spin multiplicities, are obtained employing multi-reference configuration interaction （MRCI） method and Dunning＇s correlation consistent basis sets. The analytical potential energy functions （APEFs） are fitted using the Murrell-Sorbie （MS） function and the least square method. Based on the PECs, the spectroscopic constants of the states have been determined and compared with the theoretical and experimental results available to affirm the accuracy and liability of the calculations. The root-mean-square （RMS） errors between the fitted results and the ab initio values are too little in comparison with the chemical accuracy （349.755 cm^-1）. It is shown that the present APEFs are accurate and can display the interaction between the atoms well. The present APEFs can be used to construct more complicated APEF or do some dynamic investigations.
基金Supported by the National Natural Science Foundation of China (Grant No. 20473060)Natural Science Foundation Project of CQ CSTC (Grant No. 2006BB2367)
文摘The potential energy curves for the X1 SUM_g^+,B1 DELTA_g and B'1 SUM_g^+states of C2 have been studied by using MRCl and approximate Cl methods,and are benchmarked againstthe calculations of full configuration interaction (FCl).The results obtained by MRCl method agreewith the FCl very well,and even are accurate enough to compare other approximate methods asbenchmark,when the calculations of FCI are not feasible.The approximate Cl methods mentioned in thispaper are reliable for treating chemical problems.
