On the negative hydrogen ion and its absorption coefficient

The continuous absorption coefficient of the negative hydrogen ion is discussed from the point of view of the sum rules, and it is shown that the absorption coefficient to the red of 5000 A is predominantly governed by the wave-function of the ground state of H- at distances of the order of five times the Bohr radius from the center. It appears that the wave-functions for H- now in use are not sufficiently accurate at these distances to provide reliable values for the absorption coefficient beyond 5000 A, Further, some objective criteria are stated which should enable the reliability of a given absorption curve to be tested