*PARALLEL

Parallelization directives.

.PRINT

Print level for the parallel calculation. Default:

.PRINT
 0

A print level of at least 2 is needed in order to be able to evaluate the parallelization efficiency. A complete timing for all nodes will be given if the print level is 4 or higher.

.NTASK

Number of tasks to send to each node when distributing the calculation of two-electron integrals. Default:

.NTASK
 1

A task is defined as a shell of atomic integrals, a shell being an input block. One may therefore increase the number of shells given to each node in order to reduce the amount of communication. However, the program uses dynamical allocation of work to each node, and thus this option should be used with some care, as too large tasks may cause the dynamical load balancing to fail, giving an overall decrease in efficiency. The parallelization is also very coarse grained, so that the amount of communication seldom represents any significant problem.