Long-range interactions between aHe(2S3)atom and a

Abstract

Long-range interactions between a He(2 3 S) atom and a He(2 3 P ) atom for like isotopes AbstractFor the interactions between a He(2 3 S) atom and a He(2 3 P ) atom for like isotopes, we report perturbation theoretic calculations using accurate variational wave functions in Hylleraas coordinates of the coefficients determining the potential energies at large internuclear separations. We evaluate the coefficient C 3 of the first order resonant dipole-dipole energy and the van der Waals coefficients C 6 , C 8 , and C 10 for the second order energies arising from the mutual perturbations of instantaneous electric dipole, quadrupole, and octupole interactions. We also evaluate the coefficient C 9 of the leading contribution to the third order energy. We establish definitive values including treatment of the finite nuclear mass for the 3 He(2 3 S)-3 He(2 3 P ) and 4 He(2 3 S)-4 He(2 3 P ) interactions.

Long-range interactions forHe(nS)–He(n′S)andHe(n

“…are from the second-order energy correction, and C 9 (M, β) is from the third-order energy correction [1]. The detailed expressions for C n and their evaluation in Hylleraas coordinates can be found in [1].…”

Long-range interactions of excited He atoms with the alkaline earth atoms Mg, Ca, and Sr

“…[24][25][26][27] Hence, the uncertainties of the dispersion coefficients reported in our paper are mainly determined by the completeness of the basis sets and the effectiveness of the model Hamiltonians for the alkaline earth atoms. The uncertainties of the present calculations can be estimated from the uncertainties of the dispersion coefficients for interactions of the alkaline earth atoms with the ground states of H and He.…”

“…[24][25][26][27][28] The wavefunction can be expanded in terms of the Hylleraas-type basis functions…”

Long-range states in excited ultracold3He*–4He* dimers

“…where f 3Λ is an R-and Λ-dependent retardation correction [13], λ -= λ/(2π) = 3258.12a 0 where λ is the wavelength for the 2s 3 S-2p 3 P transition and the parameters C nΛ were taken from Zhang et al [14]. Again, motivated by our study of the …”