Comment of the possibility of Ramsauer-Townsend minima in $e$-${\mathrm{H}}_2$ and $e$-${\mathrm{N}}_2$ scattering

Recent measurements of electron mobilities in hydrogen and nitrogen by Freeman and Wada [Bull. Am. Phys. Soc. 25, 1114 (1980); Phys. Rev. A 24, 1066 (1981)] have led these authors to propose Ramsauer-Townsend minima in the cross sections for $e$-${\mathrm{H}}_2$ and $e$-${\mathrm{N}}_2$ scattering. Examination of existing experimental and theoretical data for these systems strongly suggests that such structures are not present in these gases. It is argued that a temperature-dependent systematic error in the measurements of Freeman and Wada may be responsible for the appearance of minima in their cross sections.