Distribution of the virialisation parameter β_vir for haloes with mass M > 3 × 10¹³  M_⊙   h^-1. β_vir using the potential energy obtained through direct summation W_DS, which was defined in Eq. (37), is shown in orange with upward hatching, and β_vir using W, defined in Eq. (33), is shown in blue with downward hatching. The vertical black lines visualise our criterion for virialisation, i.e. | β_vir |  < 0.2.