text: In a previous study, where the magnetic properties of 
  Ho thin ﬁlms were investigated by MC simulations of a 
  Heisenberg model with easy-plane single-ion anisotropy 
  and six out-of-plane coupling constants (as obtained by 
  experimental neutron scattering measurements16) on a 
  HCP lattice14,15, it was found that for thicknesses compa- 
  rable with the helical pitch the phase diagram landscape 
  is quite diﬀerent from what we ﬁnd here. 
  Indeed, for 
  n = 9 − 16, three diﬀerent magnetic phases could be sin- 