The structure of the PSI3 Source Tree

Your working copy of the PSI3 source code includes a number of important subdirectories:

• $PSI3/lib - Source files for OS-independent ``library'' data. This includes the main basis set data file (pbasis.dat) and the PSI3 program execution control file (psi.dat), among others. These files are installed in $prefix/share.

• $PSI3/include - Source files for OS-independent header files, including physconst.h (whose contents should be obvious from its name), psifiles.h, and ccfiles.h, among others. These files are installed in $prefix/include.

• $PSI3/src/util - Source code for the utility program tocprint. (Note that the tmpl module is no longer used and will eventually disappear.)

• $PSI3/src/lib - Source code for the libraries, including libpsio, libipv1, libchkpt, etc. The include files from the library source are used directly during the compilation of PSI to avoid problems associated with incomplete installations. Some include files are architecture-dependent and go in an include subdirectory of the compilation (object) directory.

• $PSI3/src/bin - Source code for the executable modules.

After compilation and installation, the $prefix directory contains the executable codes and other necessary files. NB: The files in this area should never be directly modified; rather, the working copy should be modified and the PSI3 Makefile hierarchy should handle installation of any changes. The structure of the installation area is:

• $prefix/bin - The main executable directory. This directory must be in your path in order for the driver program, psi3, to find the modules.

• $prefix/lib - The PSI3 code libraries. (NB: The description of PSI3 Makefiles later in this manual will explain how to use the libraries.)

• $prefix/include - Header files. These are not actually used during the compilation of PSI but are useful for inclusion by external programs because they are all in the same directory.

• $prefix/share - OS-independent data files, including basis set information. (Do not edit this file directly; any changes you make can be overwritten by subsequent make commands.)

• $prefix/doc - PSI3 documentation, including installation, programmer, and user manuals.