Garberoglio Giovanni, Harvey Allan H, Lang Jakub, Przybytek Michał, Lesiuk Michał, Jeziorski Bogumił
European Centre for Theoretical Studies in Nuclear Physics and Related Areas (FBK-ECT*), Trento I-38123, Italy.
Trento Institute for Fundamental Physics and Applications (INFN-TIFPA), via Sommarive 14, 38123 Trento, Italy.
J Chem Phys. 2024 Oct 14;161(14). doi: 10.1063/5.0232505.
We develop a surface for the electric dipole moment of three interacting helium atoms and use it with state-of-the-art potential and polarizability surfaces to compute the third dielectric virial coefficient, Cɛ, for both 4He and 3He isotopes. Our results agree with previously published data computed using an approximated form for the three-body polarizability and are extended to the low-temperature regime by including exchange effects. In addition, the uncertainty of Cɛ is rigorously determined for the first time by propagating the uncertainties of the potential and polarizability surfaces; this uncertainty is much larger than the contribution from the dipole-moment surface to Cɛ. Our results compare reasonably well with the limited experimental data. The first-principles values of Cϵ computed in this work will enhance the accuracy of primary temperature and pressure metrology based on measurements of the dielectric constant of helium.
我们为三个相互作用的氦原子的电偶极矩开发了一个表面，并将其与最先进的势能和极化率表面一起用于计算 4He 和 3He 同位素的第三介电维里系数 Cɛ。我们的结果与先前使用三体极化率的近似形式计算出的数据一致，并且通过纳入交换效应扩展到了低温范围。此外，首次通过传播势能和极化率表面的不确定性严格确定了 Cɛ 的不确定性；该不确定性远大于偶极矩表面对 Cɛ 的贡献。我们的结果与有限的实验数据相当吻合。这项工作中计算出的 Cϵ 的第一性原理值将提高基于氦介电常数测量的基本温度和压力计量的准确性。
