Thermodynamic Properties and Critical Behavior of Spin-Polarized Atomic Hydrogen (H?) Using the Quantum Second-Virial Coefficient

The quantum–mechanical formulations for the second-virial, and acoustic virial, coefficients are derived spin-polarized atomic hydrogen (H?). dependence of these on temperature T as well nuclear polarization $$\zeta \;$$ is analyzed. This done first time. main inputs in computations scattering phase shifts, which obtained using Lippmann–Schwinger equation, with Silvera triplet-state potential. Starting comprehensive calculations thermophysical properties this system performed ranging from 1 µK to 100 K, varying 0 1. These include, addition quantum second-virial coefficient virial coefficient: pressure–polarization–temperature $$\left( {P {-} \zeta T} \right)$$ behavior, entropy (per atom), speed sound, correction (to total internal energy per atom unit density), specific heat capacity density). Boyle Joule inversion determined. T-dependence properties, related quantities, explored. As expected, most evident low-T limit, where effects predominate. corresponding $$\zeta$$ -dependence becomes noticeable at 80 K below. It observed that tend decrease increasing . Comparison present results previous included whenever possible. overall agreement very good. lowered, disruptive thermal weakened relative attractive interactions between atoms. Consequently, H? gas makes a transition state higher order lower entropy—Bose–Einstein condensation (BEC). explored carefully.