Line mixing in the Raman Q branch in D2 and mixtures of D2 in He and Ar

Weak mixing coefficients for D2 and D2-He mixtures at 305.2 and 100.7 K are reported and compared with ab initio quantal calculations. The measurements support but do not provide a critical test of the calculations. Measurements of 50% D2 in Ar at 305.2 K are at variance with the measurements in the pure gas and in mixtures with He and below 20 amagat exhibit an increasing line asymmetry with decreasing density. The results are also at variance with the asymmetries measured in 5% H2 in Ar.