The full width at half maximum of the He I line 6678 Å versus electron density. Our FWHM calculations for this line by including Doppler broadening (), binary approximation (–––), and dynamical screening effect (– – –) are compared with results of Gigosos et al. for pink circle (∘) independent and turquoise circle (∘) interacting particles [18, 19], (×) Bassalo et al. [41], (⊲) Kelleher [46], orange circle (•) Pérez et al. [27], (□) Mijatović et al. [47], (⋄) Vujičić et al. [48], (*) Milosavljević and Djeniže [31], and (+) Griem [1].