  The hole--spectral functions and from these the spectroscopic factors have
been calculated in an Galilei--invariant way for the ground state wave
functions resulting from spherical Hartree--Fock calculations with projection
onto zero total linear momentum before the variation for the nuclei 4He, 12C,
16O, 28Si, 32S and 40Ca. The results are compared to those of the conventional
approach which uses the ground states resulting from usual spherical
Hartree--Fock calculations subtracting the kinetic energy of the center of mass
motion before the variation and to the results obtained analytically with
oscillator occupations.
