DALTON is designed to exit gracefully if there is not enough memory at some stage of the calculation. Wherever possible, it will indicate how much additional memory is required for this particular section. This does not exclude the possibility that the calculation will use even more memory at later stages of the calculation. If DALTON aborts in the response calculation, it may be possible to proceed by resetting the number of perturbations handled simultaneously (see Sec. 25.1.15). Otherwise, some redimensioning will be necessary.
The program use approximately 6.5 Mw of memory allocated as common
blocks and similar data structures. Most of the memory used during the
calculation is taken from a large work array. The size of this work
array is supplied to the program as a shell
variable, MEMWRK.
How this is done is exemplified in the chapter on how to get started
(Chapter 5). This makes it easy
to give the program the memory needed for a given calculation. If no
value to the shell
variable is supplied, the program will use the default value which is
determined at installation time from the variable
INSTALL_WRKMEM in the preprocessor
directives.