  Steepest-entropy-ascent quantum thermodynamics (SEAQT) is an intriguing
approach that describes equilibrium and dynamic processes in a self-consistent
way. The applicability is limited to mainly gas phases because of a complex
eigenstructure (eigenvalues and eigenfunctions) of solid or liquid phases. In
this contribution, the SEAQT modeling is extended to a condensed phase by
constructing a simplified eigenstructure (so-called pseudo-eigenstructure), and
the applicability is demonstrated by calculating the thermal expansion of
metallic silver in three cases: (a) at stable equilibrium, (b) along three
irreversible paths from an initial nonequilibrium state to stable equilibrium,
and (c) along an irreversible path between two stable equilibrium states. The
SEAQT framework with an anharmonic pseudo-eigenstructure predicts reasonable
values for equilibrium thermal expansion. For the irreversible cases
considered, the SEAQT approach makes it possible to predict the time-dependence
of lattice relaxations from the initial state to the final state.
