subroutine walker_death_spawn()
! this routine is for the 2nd RK step, in which the list k2, which
! has to be combined with the original y(n) walker list, is created
! since the diagonal death/cloning step cannot be done on the currently
! iterated on list y(n) + k1/2, treat the diagonal step, like a spawning
! step and store it also in the spawned array
! possible considerations: maybe the original spawned list is then
! too small, if we have a really big y(n) + k1/2 list, from which
! essentially all determinants get stored into the spawned list
! during the death/cloning step..
! talk about that with ali!
character(*), parameter :: this_routine = "walker_death_spawn"
end subroutine walker_death_spawn