The SAPT group of codes can be interfaced with virtually any integral/SCF program. A short description of the elements of the interfacing process is presented here. The existing interfaces can be used as a template for the creation of new interfaces. A short listing of what the tran program needs follows.
Most of the information is read by a small interface program from the integral/SCF program files and then rewritten into a simple form that the next stages of the process can easily understand. Modifications to the transformation program must be made to read in the two-electron integrals (in trans.f, atmtr.f, and trnn.f modules). Notice also the common block SCFPACK which contains logical variables indicating which integral/SCF program is used. This common block must be changed throughout the program to include a logical variable for any new integral/SCF program. Finally, in the driver subroutine trans.F, make sure that there is a correct setting of the logical input record length for the new integral/SCF program.