Intermolecular potentials from proton spin–lattice relaxation time in H2–Ar and H2–N2 gas mixtures

Proton spin-lattice relaxation times, T1, have been measured in H2–Ar and H2–N2 gas mixtures as a function of density (10 < ρ < 70 amagat), composition (~ 18–65%), and temperature (300–600 K) with a 30 MHz spin-echo spectrometer using phase sensitive detection. These data together with the T1 data obtained by Foster and Rugheimer and by Williams in these mixtures below 300 K have been analysed using the Bloom–Oppenheim theory. Models for intermolecular potentials to explain the T1 data have been proposed. It is found that the relative anisotropy in the attractive part of the intermolecular potential which fits the T1 data best compares well with that evaluated using polarizability data.