Ab Initio Transport Coefficients of Gaseous Hydrogen

The spherical version of the hydrogen intermolecular potential ${\phi_{\rm P}}$ recently determined in ab initio calculations by Patkowski et al. was used to calculate the viscosity and thermal conductivity of hydrogen using a full quantum-mechanical formalism. Viscosities in the temperature range 203 K to 394 K were compared with recent high-accuracy (uncertainty of 0.084 %) measurements of May et al. The measured viscosities all fall in a range between 0.02 % and 0.06 % below the calculated viscosities. This close agreement supports the accuracy of ${\phi_{\rm P}}$ . Classical calculations of the viscosity with ${\phi_{\rm P}}$ fall in a range between 0.4 % and 1.3 % below the experimental values. In the lower temperature range 20 K to 300 K, other measurements typically lie above the theoretical values by a few percent. Above 400 K, measurements fall below the theoretical values by a fraction that increases with temperature, reaching ?4% at 2000 K. For normal hydrogen, the average fractional difference between the calculated thermal conductivity in the temperature range 21 K to 384 K and measurements reported in six publications is (0.1 ± 1.1) %. For para-hydrogen in the temperature range 20 K to 275 K, the average fractional difference between calculations and measurements reported in three publications is (?0.7 ± 1.2) %. At higher temperatures (600 K to 2000 K), measurements range between 4 % and 10 % below the calculated values.