  The thermodynamics of solid (hcp) He-4 is studied theoretically by means of
unbiased Monte Carlo simulations at finite temperature, in a wide range of
density. This study complements and extends previous theoretical work, mainly
by obtaining results at significantly lower temperatures (down to 60 mK) and
for systems of greater size, by including in full the effect of quantum
statistics, and by comparing estimates yielded by different pair potentials.
All the main thermodynamic properties of the crystal, e.g., the kinetic energy
per atom, are predicted to be essentially independent of temperature below 1 K.
Quantum-mechanical exchanges are virtually non-existent in this system, even at
the lowest temperature considered. However, effects of quantum statistics are
detectable in the momentum distribution. Comparison with available measurements
shows general agreement within the experimental uncertainties.
