arXiv:1409.5985 · Physical Review A
Relativistic calculations of C6 and C8 coefficients for strontium dimers
S. G. Porsev, Marianna S. Safronova, Charles W. Clark
Abstract
The electric-dipole and quadrupole polarizabilities of the $5s5p{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{1}^{o}$ state and the ${C}_{6}$ and ${C}_{8}$ coefficients for the ${}^{1}{S}_{0}+{\phantom{\rule{0.16em}{0ex}}}^{1}{S}_{0}$ and ${}^{1}{S}_{0}+{\phantom{\rule{0.16em}{0ex}}}^{3}{P}_{1}^{o}$ 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 ${}^{1}{S}_{0}\text{\ensuremath{-}}{}^{3}{P}_{1}^{o}$ transition vanishes. The accuracy of calculations is analyzed and uncertainties are assigned to all quantities reported in this work.