# Defining the domain

All simulations, whether using an embedded boundary (EB) or not, are specified on a simple cuboid domain. The low and high corners of the cuboid are defined by the `prob_lo` and `prob_hi` inputs.

The following inputs are defined using the `geometry` prefix.

| Description | Type | Default
--- | --- | --- | ---
coord_sys | Coordinate system used in simulation. Only Cartesian coordinates (`coord_sys = 0`) are supported. | Int | 0
is_periodic | 1 for true, 0 for false (one value for each coordinate direction) | Int | 0 0 0
prob_lo | Low corner of physical domain (physical not index space) | Reals | 0 0 0
prob_hi | High corner of physical domain (physical not index space) | Reals | 0 0 0

Attention

MFIX-Exa geometry restrictions:

- There is no support for 1D or 2D simulation domains.

- Cartesian is the only supported coordinate system.