Centre-of-mass problem for hadrons from the quark model

We study the use of the Peierls-Yoccoz and the Peierls-Thouless procedures to remove the centre-of-mass motion from the Hartree-Fock states in order to construct hadrons in terms of the relativistic quark model. Using explicitly the nonrelativistic harmonicoscillator wave functions, we show the consequence of the above procedures and the point to take care when several Hartree-Fock states are linearly combined.