Long-range interactions of the thallium 7 2S1/2 state and broadening and shift of the thallium violet and green lines by rare gases

Abstract
The long‐range interaction coefficients (C6, C8, C10) of the Tl(7 S1/2) atom with rare gases are calculated. The pressure‐induced broadening and shift of the thallium resonance lines in the presence of rare gases are then calculated using these long‐range coefficients and impact theory. We find that higher order van der Waals forces are not negligible compared to the leading −C6/R6 dispersion force in terms of their contributions to the broadening and shift.