Again node 0 is charged with accessing the initial input file. The data read from this file are broadcast to the other participating nodes. In the version of the program used for this investigation, each node creates and writes data to a separate disk file of integrals. Other versions use only a single file. The final program, pscf , reads the integrals and solves the equations.
All file access is sequential.
An application-specific library is included with the code. The code for this library is also included in the distribution. Funding for their exploration has been provided by the U.S. Department of Energy and the High Performance Computing and Communication Program. Trace data was obtained using the Pablo trace capture library.