Long-range interactions of the Sr⁺ ion

A number of properties of the low-lying states of the Sr⁺ ion are evaluated by diagonalizing a semiempirical Hamiltonian in a large dimension single electron basis. These properties include the oscillator strengths connecting the low-lying states, the quadrupole moments, and the polarizabilities. In addition, the long-range dispersion coefficients for the states of this ion interacting with a number of atoms are given. The polarizabilities and dispersion coefficients can be used to estimate frequency shifts of the Sr⁺ 5s→4d clock transition due to background fields, including the blackbody radiation shift, and shifts due to collisions with a buffer gas.