AI 中文总结
本文研究强磁场下轻双原子分子的对角Born-Oppenheimer修正，发现该修正对振动频率产生近场无关偏移，超出磁白矮星大气谱线精度，且电子关联影响显著。
AI 中文摘要
研究了强磁场下轻双原子分子电子结构中对角Born-Oppenheimer修正（DBOC）的影响。考虑了H$_2$、HeH$^+$和LiH，分别采用Hartree-Fock（HF）近似和含单双激发的组态相互作用（CISD）方法。分析覆盖了高达$B_\parallel = 0.2$ a.u.（$4.7\times10^{4}$ T）的磁场强度，这与磁白矮星附近的天体物理条件相关。尽管该修正显著改变了总电子能量，但它随核间距平滑变化，且对场的依赖较弱，因此它作为几乎与场无关的偏移进入振动跃迁频率，使基频间隔移动约$1$ cm$^{-1}$，较高能级移动高达$15$ cm$^{-1}$。这些移动超过了目前磁白矮星大气中分子谱线可达到的$0.1$--$2.0$ cm$^{-1}$精度。HF和CISD结果的比较表明，电子关联对DBOC有不可忽略的影响，在强离子性的LiH键中最为显著。
英文摘要
The influence of the diagonal Born--Oppenheimer correction (DBOC) on the electronic structure of light diatomic molecules subjected to strong magnetic fields is investigated. H$_2$, HeH$^+$, and LiH are considered, using both the Hartree--Fock (HF) approximation and configuration interaction with single and double excitations (CISD). The analysis covers magnetic field strengths up to $B_\parallel = 0.2$ a.u. ($4.7\times10^{4}$~T), relevant to astrophysical conditions near magnetic white dwarfs. Although the correction noticeably shifts total electronic energies, it varies smoothly with internuclear distance and depends only weakly on the field, so that it enters the vibrational transition frequencies as a nearly field-independent offset, shifting the fundamental interval by about $1$~cm$^{-1}$ and the higher levels by up to $15$ cm$^{-1}$. These shifts exceed the $0.1$--$2.0$ cm$^{-1}$ accuracy currently attainable for molecular lines in the atmospheres of magnetic white dwarfs. Comparison of HF and CISD results shows that electron correlation has a non-negligible effect on the DBOC, most pronounced for the strongly ionic LiH bond.
