  Generators of the Poincar\'e group, for a free massive scalar field, are
usually expressed in the momentum space. In this work we perform a
transformation of these generators into the coordinate space. This
(spatial)-position space is spanned by eigenvectors of the Newton-Wigner-Pryce
operator. The motivation is a deeper understanding of the commutative spatial
coordinate space in QFT, in order to investigate the non-commutative version
thereof.
