  It is well known that an essentially unique free massive particle field of
given spin can be constructed as a linear combination of the annihilation and
creation operators for free single particle states. And the given spin
determines the transformation of the field components for rotations and boosts.
But the usual construction restricts translations; the components are simply
invariant under translations. This paper generalizes the construction so that
translations may have a nontrivial effect on field components.
  PACS: 11.30.Cp Lorentz and Poincare invariance
