This diagram illustrates the layout of the CGNS file for the unstructured grid used in this example.

Just below the root node of the ADF file are two nodes with the following characteristics.

Just below the CGNSBase_t node is a Zone_t node, with:

At the next level, below the Zone_t node are the following three nodes.

Below the GridCoordinates_t node are three nodes defining the grid coordinates. In the figure, only the first is shown, as follows.

Finally, below the Elements_t node are the following two nodes defining the element range and connectivity data.