# nwARGOS file structure

File names

File names used by nwARGOS need to have the form project_id.ext, with exception of the topology file, which should be named project.top, and the input file for NWChem, which should simply be project. Anything that refers to the definition of the chemical system can be used for project, as long as no periods or underlines are used.
The identifier id can be anything that refers to the type of calculation to be performed for the system.
The extensions ext identify the kind of information on the file, and are determined by the programs. Examples of extensions are top for the topology file, rst for the restart file and inp for the input file.

This file naming convention allows for the creation of a single topology file project.top for a chemical system with which a number of different calculations, identified with different id.

Database names

A similar convention is used to identify databases used by the setup programs nwTOP, nwRST and nwSGM. Force field database names have the form forcefield_level.ext, where forcefield stands for any of the supported force fields. The source of the data is identified by level, and can be

level | Description | Availability
--- | --- | ---
s | original published data | public
x | additional published data | public
u | user preferred data | private
r | user defined run specific data | private

Only the level s and x databases are publicly available. The user is responsible for the private level u and r databases.

Other database files include the force field independent fragment libraries and the solvation restart files.