.. _fort18:

Fort.18: Domain Decomposition Data
==================================

Overview
--------

The fort.18 file is a specialized file used specifically for parallel (MPI) execution of ADCIRC, commonly known as PADCIRC. This file is automatically generated by the ``adcprep`` executable and should not be manually created or modified.

Location and Generation
-----------------------

Unlike most ADCIRC input files that reside in the main run directory, the fort.18 file is distributed across multiple locations:

* Generated by: ``adcprep`` executable
* Location: One copy exists in each PE* subdirectory (e.g., PE0000, PE0001, etc.)
* Timing: Created during the pre-processing phase, before launching a parallel ADCIRC run