The electric dipole and quadrupole polarizabilities of the $5s5p~^3\!P_1^o$ state and the $C_6$ and $C_8$ coefficients for the $^1\!S_0 +\, ^1\!S_0$ and $^1\!S_0 +\, ^3\!P_1^o$ dimers of strontium are calculated using a high-precision relativistic approach that combines configuration interaction and linearized coupled-cluster methods. Our recommended values of the long range dispersion coefficients for the $0_u$ and $1_u$ energy levels are $C_6(0_u)=3771(32)$ a.u. and $C_6(1_u)= 4001(33)$ a.u., respectively. They are in good agreement with recent results from experimental photoassociation data. We also calculate $C_8$ coefficients for Sr dimers, which are needed for precise determination of long-range interaction potential. We confirm the experimental value for the magic wavelength, where the Stark shift on the $^1\!S_0$-$^3\!P_1^o$ transition vanishes. The accuracy of calculations is analyzed and uncertainties are assigned to all quantities reported in this work.
A Comparative Analysis of Non-relativistic and Relativistic Calculations of Electric Dipole Moments and Polarizabilities of Heteronuclear Alkali Dimers
Fragmentation of the $^4$He$_2$ dimer by relativistic highly charged projectiles in collisions with small kinetic energy release
本文从理论上研究了氦二聚体$^4$ He $_2$在与相对论高电荷粒子碰撞中碎裂成单电荷离子的过程。我们讨论了驱动这一过程的主要机制，重点是在一个单一的碰撞与弹丸的二聚体的两个原子位点的直接电离所造成的碎片。这种直接机制主导了He $_2$ $\to $ He $^+$ + He $^+$破裂事件，其中出现的离子碎片的动能低于$4$ - $5$ eV。我们探讨的能量和角分布的He $^+$离子产生的碰撞与$1$和$7$ GeV/u U $^{92+}$弹丸，并表明它们的形状显着影响相对论和高阶效应之间的相互作用的弹丸和二聚体。我们还表明，能谱的形状是相当敏感的他$_2$二聚体的结合能，可以利用其精确的测定。计算出直接机制对He $_2$通过$1$和$7$ GeV/u U $^{92+}$碎裂的总截面的贡献分别为$3.65$ Mb和$2.4$ Mb，约占该截面的一半。
Electric Dipole Moments and Static Dipole Polarizabilities of Alkali--Alkaline-Earth Molecules: Non-relativistic versus relativistic coupled-cluster theory analyses
Investigating Roles of Triple Excitations for High-precision Determination of Clock Properties of Alkaline Earth Metal Singly Charged Ions
Atomic, Molecular and Optical Physics Division, Physical Research Laboratory（物理研究实验室原子、分子与光学物理分部）；Indian Institute of Technology Gandhinagar（甘地纳加尔印度理工学院）
