We investigate localization properties of two correlated electrons in
a one-dimensional disordered system. The results found for the ''bag m
odel'' in center-of-mass and relative coordinates are compared with th
ose obtained earlier [Frahm et al., Europhys. Lett., 31, 1995, 169] by
using particle coordinates. We show that results for the two particle
localization length obtained by using the bag model depend on discret
ization and/or boundary conditions (C) 1998 Elsevier Science Ltd. All
rights reserved.