Nwchem

NWChem

The NWChem home page is at external link: http://www.nwchem-sw.org/ .

NWChem-6.6 has been compiled to use the Intel MPI and MKL libraries. Both are available for use on Invicta. To use nwchem-6.1.1, proceed as follows.

-bash-3.2$ module purge
-bash-3.2$ module load nwchem/6.6
-bash-3.2$ module list
Currently Loaded Modulefiles:
  1) intel/license      2) intel_mpi/5.1.1
  3) intel/16.0.047     4) nwchem/6.6

Acknowledging

Please cite the following reference when publishing results obtained with NWChem.

  1. M. Valiev, E.J. Bylaska, N. Govind, K. Kowalski, T.P. Straatsma, H.J.J. van Dam, D. Wang, J. Nieplocha, E. Apra, T.L. Windus, W.A. de Jong, "NWChem: a comprehensive and scalable open-source solution for large scale molecular simulations" Comput. Phys. Commun. 181, 1477 (2010)

.nwchemrc

You will need a file called $HOME/.nwchemrc which can contain the following.

Running NWChem-6.6 on Napier

A very simple job script might look as follows.

NWChem must be run in "direct" mode. That is, re-calculating integrals on demand, and not saving them to disk. This is especially important when running on a large cluster with a shared filesystem. In addition, it has been observed that direct mode is at least 2-3 times faster than using temporary files on disk. For example, when running an MP2 computation, the following option MUST be set: "TASK DIRECT_MP2 optimize".

Running on Bantam

This is currently not available.

Benchmarks

The C240_PBEO benchmark was run on SID, Invicta and Napier (2 iterations only).

ncpustotal iterative time (s)total iterative time (s)-do--do--do-
 SID (6.1)Invicta (6.1.1, 16 core, MPI-TS)Invicta (6.3, 16 core, MPI-TS)Napier (6.6, 24 core, MPI-TS)Napier (6.6, 24 core, OPENIB)
484725.4   887.4
64 1382.9612.9692.5 
961363.4 427.4607.3505.4
128 716.7321.9421.7423.8
192770.5339.0230.3327.0332.0
256   276.6(361.0 on Iden)
384457.4280.3157.7xx
512  162.3xx

Other Information

Please consult the NWChem Web site: external link: http://www.nwchem-sw.org/index.php/Main_Page and MediaWiki Forum: external link: http://www.nwchem-sw.org/index.php/Special:AWCforum .

Full on-line documentation for NWChem v6.0 is here: external link: http://www.nwchem-sw.org/index.php/NWChem_Documentation .