The precompiler PREXPLOR makes use of a template file (called ``PREXPLOR.DIM") to adjust the dimensioning of the X-PLOR program. If any dimension is exceeded during execution of X-PLOR, the user has to modify ``PREXPLOR.DIM" in the appropriate machine-dependent directory. The fact that an array dimension is exceeded is indicated by an error message of the form
%<subroutine>-ERR: ABCD is exceeded.The program terminates execution in batch mode and it will produce a severe error message in interactive mode. The user has to modify the specified parameter in the ``prexplor.dim" file and reinstall the program as described in the previous section.
Error messages can occur when the quasi-dynamic HEAP space is exceeded. On machines with static memory management, the ``HEAPDM" parameter has to be increased. On most machines, the heap is automatically expanded until the site-dependent maximum memory allocation is exceeded. In that case, the site-dependent quota (such as PAGEFILE quota on VAX) has to be increased, or the use of the HEAP has to be reduced. One way to reduce the needed HEAP space during any kind of structure factor calculation is to reduce the ``MEMOry" specification within the xrefin FFT statement (Section 12.3).