Numerical evaluations of the isotopic shifts and lowest-order QED corrections for the ground 1¹S-states of the {}³He and {}⁴He atoms

The both mass-dependent and field shift components of the isotopic shifts and the lowest order QED corrections for the ground (singlet) $1^1S(L = 0)-$states of the ${}^{3}$He and ${}^{4}$He atoms are determined to high accuracy. For the same states we also evaluated the lowest-order QED corrections and the corresponding recoil (or finite mass) corrections. In our calculations we have used the new (corrected) formula for the recoil correction to the lowest-order QED correction which can be applied to atoms/ions with arbitrary nuclear charge $Q \ge 1$.