Far-Wing Line Shapes: Application to the Water Continuum

Abstract

A far‐wing line shape theory that satisfies the detailed balance principle has been developed invoking only the binary‐collision and quasistatic approximations. This first‐principles theory has been applied to calculate the far‐wing line shapes and the corresponding absorption for H2O‐H2O and H2O‐N2 which, for historical reasons, are called the self‐ and foreign‐broadened water continua. Using sophisticated interaction potentials that give good agreement with other transport data and the coordinate representation, in which the required traces become multidimensional integrals over the angular coordinates necessary to specify the positions before and after the collision (11‐ dimensional for the self and 9‐dimensional for the foreign continuum, respectively), we can obtain converged results using moderate computational resources. Results obtained are in very good agreement with existing laboratory data, and comparisons with an empirical continuum will be presented.