A basic AIFDEM calculation is requested by setting AIFDEM = TRUE in the $rem section. Additional job control variables dictate which types of states are included in the exciton-site basis as well as the NTO threshold that is used to truncate the expansion in Eq. (12.68). These variables and some others are described below.
For calculations on large systems, it may be desirable to break up the calculation of the AIFDEM matrix elements into batches. The user can specify can specify the first and last matrix element for a calculation with the following variables.
When computing AIFDEM matrix elements in batches, one can avoid running fragment SCF calculations for each job, by first running a job that runs only the fragment SCF calculations. These are saved in the scratch directory. These may then be read into subsequent calculations. The following variables control this utility.