BrF分子电磁偶极跃迁转动超精细微波谱模拟  

Simulation of hyperfine-rotational spectrum of electromagnetic dipole transition rotation of BrF molecules

作　　者：陈润 邵旭萍[1] 黄云霞[1] 杨晓华[1] Chen Run;Shao Xu-Ping;Huang Yun-Xia;Yang Xiao-Hua(School of Science,Nantong University,Nantong 226019,China)

机构地区：[1]南通大学理学院,南通226019

出　　处：《物理学报》2023年第4期27-34,共8页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:12004199)资助的课题。

摘　　要：本文推导了BrF振动基态(X^(1)Σ,v=0)下J=1←0的转动超精细光谱的跃迁偶极矩,总结了跃迁选择定则为:△J=±1;△F_(1)=0,±1和△F=0,±1;而且,当△F_(1)=△F时谱线强度很强,反之很弱.当能级之间存在微扰相互作用时,某些谱线由电偶极和核磁偶极跃迁共同产生,然而磁偶极仅仅贡献大约十亿分之一的光谱强度.计算所得光谱线宽和相对强度与实验结果一致.同时,在|JI_(1)F_(1)I_(2)F>基矢下对Hamilton量矩阵对角化确定了转动超精细光谱的位置,与实验误差小于1/50谱线宽度(<10-8).最后模拟了微波转动超精细光谱,所得结果有助于超精细分子光谱实验和其他相关应用研究.The transition dipole of the hyperfine-rotation spectrum of J=1←0 within the vibronic ground(X^(1)∑,v=0)state of BrF molecule is derived,and thus,the transition selection rules are summarized as follows:△J=±1;△F_(1)=0,±1 and△F=0,±1,and those of△F_(1)=△F are intense while those of△F_(1)≠△F are weak.Some spectral lines result from both the electric dipole transition and nuclear magnetic dipole transition due to perturbations,however,the magnetic dipole transition only contributes about one-billionth in the spectral intensity.The spectral linewidth is determined to be about 18 kHz by calculating the spectral transition probability.The obtained spectral linewidth and relative intensities are consistent with the experimental results.Additionally,the hyperfine-rotation spectral positions are determined by diagonalizing the Hamiltonian matrix in the basis of|JI_(1)F_(1)I_(2)F>,which is also in good agreement with the experiments within 10-8(one-fiftieth of the spectral line width).Hence,the microwave hyperfine-rotation spectrum is simulated.In addition,we find that the nuclear spin-spin interaction not only slightly shifts the hyperfine-rotation spectral positions but also changes the sequence of the spectra.As to those unavailable constants of molecules,the fairly precise molecular constants can be achieved by quantum chemical calculation,say,by employing MOLPRO program,and then the simulated spectra can guide the spectral assignment.Besides the guidance of spectral assignment,our results are also helpful for other relevant applications such as in absolute single quantum state preparation.

关 键 词：超精细结构 磁偶极跃迁矩 转动超精细谱 BrF 

分 类 号：O561[理学—原子与分子物理]