Version: SMASH-1.5
Lattice

It is possible to configure a Lattice for the 3D space, which can be useful to speed up the computation of the potentials. Note though, that this goes in hand with a loss of accuracy: If the lattice is applied, the evaluation of the potentials is carried out only on the nodes of the lattice. Intermediate values are interpolated.
The configuration of a lattice is usually not necessary, it is however required if the Thermodynamic VTK Output (see Thermodynamics VTK Output) or the Potentials_Affect_Thresholds option is enabled.
The following parameters are only required, if the Lattice section is used in the configuration file. Otherwise, no lattice will be used at all.

Sizes (array<double,3>, required, no default):
Sizes of lattice in x, y, z directions in fm.

Cell_Number (array<int,3>, required, no default):
Number of cells in x, y, z directions.

Origin (array<double,3>, required, no default):
Coordinates of the left, down, near corner of the lattice in fm.

Periodic (bool, required, no default):
Use periodic continuation or not. With periodic continuation x + i * lx is equivalent to x, same for y, z.

Potentials_Affect_Thresholds (bool, optional, default = false):
Include potential effects, since mean field potentials change the threshold energies of the actions.

For information on the format of the lattice output see Thermodynamics VTK Output. To configure the thermodynamic output, see Output Configuration.


Examples: Configuring the Lattice

The following example configures the lattice with the origin in (0,0,0), 20 cells of 10 fm size in each direction and with periodic boundary conditions. The potential effects on the thresholds are taken into consideration.

Lattice:
    Origin:    [0.0, 0.0, 0.0]
    Sizes:    [10.0, 10.0, 10.0]
    Cell_Number:    [20, 20, 20]
    Periodic: True
    Potentials_Affect_Thresholds: True