Key points are not available for this paper at this time.
A formula is developed to explain the low pressure line widths observed in the inversion spectrum of NH₃ by Bleaney and Penrose. The assumptions made are those characteristic of the statistical theory of pressure broadening. The result, which is entirely devoid of adjustable parameters, agrees with the data about as well as do the impact theories with their unreasonable collision radius.
Henry Margenau (1949) studied this question.