This diagram illustrates the layout of the upper-level nodes in the CGNS file for the two-zone structured grid example.

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

Just below the CGNSBase_t node are the two Zone_t nodes.

At the next level, each of the Zone_t nodes have the following four child nodes.

The GridCoordinates_t, FlowSolution_t, and ZoneGridConnectivity_t nodes have child nodes of their own, described in the next three figures.

Note that the names of the CGNSBase_t, Zone_t, and FlowSolution_t nodes are user defined.