Accurate Calculations of Helium Dielectric Properties Featured as Editor’s Pick

A recent publication by an international team, including scientists from NIST, the University of Warsaw, and ECT*, has been recognized as an Editor’s Pick in The Journal of Chemical Physics. The paper presents a first-principles calculation of the third dielectric virial coefficient of helium, with no uncontrolled approximations. By rigorously propagating uncertainties from the potential, polarizability, and electric dipole-moment surfaces, the study achieves results that are far more accurate than the limited experimental data available. These findings are expected to improve the precision of primary temperature and pressure metrology, particularly in dielectric gas thermometry.

Building on similar groundbreaking results for the second and third density virial coefficients, this work further underscores the growing role of first-principles calculations in primary metrology. It marks the culmination of two decades of theoretical and computational research, signaling a paradigm shift where the accuracy of computational results now exceeds that of the most precise experimental measurements. The increasing importance of ab initio calculations in gas-based metrology is also highlighted in a recent review.