Using TONTO to do calculations

Using TONTO to do calculations consists of two parts. The first part is to write an input file for the main program that you want to use. The second part is to actually run the program.

The second part is very easy and will be described first, in the next section. The rest of the chapter will be concerned with how to write input files for the most common executables in the TONTO system.

How to run a TONTO calculation

TONTO is different from most programs used in computational chemistry because it does not have a single "main program" (although for convenience a few common "main programs" are already set up for you to use). Instead, TONTO consists of about fifty independent modules, and most of these can be compiled and executed to do calculations.

By convention, the executable program associated with any module with name XXXX is always called run_xxxx.x.

The module which probably will be used most often is MOL, since it contains routines which deal with "molecular data". The executable, or "main program" associated with this module is called run_mol.x.

The procedure for running any main program is always the same. Simply type the name of the executable program.

For example, to run the run_mol.x program, simply type

run_mol.x

The main program may, or may not, require an input file which contains instructions for what it is to do. If an input file is required, it must always be called stdin.

As part of its execution, the program will usually produce some output, which will be the results of the calculation. If output is produced, it will always be called stdout. Note that other files may also be produced. The names of these files, and what is contained in them, will depend on the nature of the calculation specified in the input file.