:orphan:
 

.. index:: *PARALLEL
.. _*PARALLEL:

==========
\*PARALLEL
==========

Parallelization directives.


.. index:: .PRINT
.. _PARALLEL_.PRINT:

.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.


.. index:: .NTASK
.. _PARALLEL_.NTASK:

.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.