Geometric quantities of lower doubly excited bound states of helium  

作　　者：Chengdong Zhou Yuewu Yu Sanjiang Yang Haoxue Qiao 周成栋;余岳武;杨三江;乔豪学(School of Physics and Technology,Wuhan University,Wuhan 430072,China;College of Physics and Electronic Science,Hubei Normal University,Huangshi 435002,China)

机构地区：[1]School of Physics and Technology,Wuhan University,Wuhan 430072,China [2]College of Physics and Electronic Science,Hubei Normal University,Huangshi 435002,China

出　　处：《Chinese Physics B》2022年第3期160-164,共5页中国物理B（英文版）

基　　金：Project supported by the National Natural Science Foundation of China (Grant No. 12074295)。

摘　　要：Expectation values of single electron and interelectronic geometric quantities such as <γ>,<γ_(12)> ,<γ_(<)> , <γ_(>)>,<cosθ_(12)> and <θ_(12)> are calculated for doubly excited 2pnp ^(1)P^(e)(3 ≤ n ≤ 5), 2pnp ^(3)P^(e)(2 ≤ n ≤ 5)and 2pnd ^(1,3)D°(3 ≤ n ≤ 5) states of helium using Hylleraas-B-spline basis set. The energy levels converge to at least 10 significant digits in our calculations.The extrapolated values of geometric quantities except for <θ_(12)> reach 10 significant digits as well;<θ_(12)> reaches at least 7 significant digits using a multipole expansion approach. Our results provide a precise reference for future research.

关 键 词：doubly excited states unnatural parity Hylleraas-B-spline geometric quantities 

分 类 号：O562.4[理学—原子与分子物理]