NIST-JANAF thermochemical tables. III. Diatomic hydrogen halide gases

The spectroscopic and thermodynamic properties of the four diatomic hydrogen halide molecules-HX(g), where X=F, Cl, Br, and I-have been reviewed. Four revised thermochemical tables result from this critical review. The revisions involved the consideration of new spectroscopic information and the use of a direct summation over states for the generation of the thermochemical tables. Compared to previous calculations, the entropies at 298.15 K are unchanged, but the high temperature values (T>4000 K) are significantly different. (C) 2004 American Institute of Physics.