The default configuration for the Lattice depends on the modus and is in most cases based on some heuristic to approximate the region in space that particles usually reach during the evolution.

Collider

The maximum expected longitudinal velocity is approximated to the speed of light \(v_z=1\) and the maximum expected velocity in each transverse direction is \(v_x=v_y = 0.7\). Assuming an \(R=5\) fm nucleus that is contracted along the z-direction by \(\gamma = \frac{\sqrt{s}_{NN}}{2m_N}\) and the particles propagating until end time, we end up with

\[ z_{\rm max} = \frac{5\,{\rm fm}}{\gamma} + t_{\rm end} \]

\[ x_{\rm max} = y_{\rm max} = 5\,{\rm fm} + 0.7 t_{\rm end}\,. \]

The lattice then covers the range \( -x_{\rm max} < x < x_{\rm max}\) , \( -y_{\rm max} < y < y_{\rm max}\) and \( -z_{\rm max} < z < z_{\rm max}\) . The cell size in x and y is 0.8 fm and the cell size in z-direction is contracted to \(\frac{0.8\,{\rm fm}}{\gamma}\)

Box and ListBox

The lattice covers exactly the entire box from 0 to box length in x,y and z. The cell size is 0.5 and only in this case the lattice is periodic.

Sphere

Since the Sphere has an initial Radius, the maximum distance in all directions can be estimated to

\[ x_{\rm max} = y_{\rm max} = z_{\rm max} = R_0 + t_{\rm end} \]

using the speed of light as a maximum expansion velocity. The cell size is 0.8 fm in each direction.

List

The default for the list modus is constructed assuming it is used for an afterburner calculation. As in the case for the collider we take th speed of light for the maximum longitudinal expansion velocity and 0.7 fo the transverse one. The cells size is 0.8 fm in ach direction, meaning they are not lorentz contracted as they would be in the case of the collider setup.