  The low-lying cluster states of 6He (a+n+n) and 6Li (a+n+p) are calculated by
the real-time evolution method (REM) which generates basis wave functions for
the generator coordinate method (GCM) from the equation of motion of Gaussian
wave packets. The 0+ state of 6He as well as the 1+, 0+ and 3+ states of 6Li
are calculated as a benchmark. We also calculate the root-mean-square (r.m.s.)
radii of the point matter, the point proton, and the point neutron of these
states, particularly for the study of the halo characters of these two nuclei.
It is shown that REM can be one constructive way for generating effective basis
wave functions in GCM calculations.
