Geometry of H-paracontact metric manifolds

We introduce and study H-paracontact metric manifolds, that is, paracontact metric manifolds whose Reeb vector field xi is harmonic. We prove that they are characterized by the condition that xi is a Ricci eigenvector. We then investigate how harmonicity of the Reeb vector field xi of a paracontact metric manifold is related to some other relevant geometric properties, like infinitesimal harmonic transformations and paracontact Ricci solitons.