Other PSI3 C Libraries

There are several other PSI C libraries besides the previously-mentioned libipv1.a, libpsio.a, and libciomr.a:

libchkpt.a This library provides many routines for reading from and writing to the ``checkpoint'' file, file30. There is generally a different function associated with each quantity in file30 (such as the SCF energy, nuclear repulsion energy, geometry, basis set information, etc). This library uses the libpsio.a library to do its input and output. It replaces an older library libfile30.a which served the same purpose but which used the old I/O from libciomr.a.

libiwl.a The new format for storing two-electron integrals is IWL, or ``integrals with labels.'' The library libiwl.a provides functions for reading and writing files in the IWL format. The code was written with the goal that it could be easily modified to allow for more than 256 basis functions. Its current limit is 32768 basis functions.

libqt.a This is the ``Quantum Trio'' library, which contains a number of very experimental functions or functions which don't otherwise fit anywhere else.

In this section we will consider these libraries in greater detail.