I've just checked in the results for NWChem 6.3 compiled on Centos (also 6.3). But in the meanwhile, others have shot ahead by forking the speed test and checking in their own results:
- Eric Berquist, a grad student at the Uni of Pittsburgh, has checked in results for Dalton, ORCA, and Q-Chem.
- Michael Banck, Debichem guru, has checked in results for all those packages available on Debian 7 (and presumably Ubuntu and other derivatives) namely NWChem, MPQC, and PSI4, as well as ERKALE.
Dudes, I salute you.
Let's start with my results. Rather than repeat the table here, you can check out the figures on the Github page. The summary is that NWChem is quite a bit faster at geo-opts than ERKALE. This is a combination of more steps in the geo-opt, and faster energy calculations. So if you are using some of ERKALE's other features, it would probably make sense to geo-opt first with NWChem. I did recompile ERKALE with "-O3 -ffast-math -funroll-loops -fPIC -march=native" and got a 10% improvement but that's not enough to change things.
From the other calculations, what do we now know? Well all of the packages tested can actually do geo-opts at the HF/6-31G and B3LYP/6-31G level of theory. Figuring this out by looking at their websites is not always as easy as you might think. Also worth noting is the relative slowdown when using B3LYP versus HF. In some cases the slowdown is of the order of 30-40%, in other cases the DFT calculations are twice as slow.
Michael's show that NWChem is faster than any of the other Open Source QM packages tested. Very useful information; again, it points at a large time-saving by using NWChem for the initial geo-opt before turning to whatever package you need for the subsequent analysis. Eric has compared several proprietary packages (I was going to say commercial but I can't tell if ORCA is available for purchase) and Q-Chem is much faster than ORCA and Dalton.
What we haven't looked at is scaling. Maybe the orders all change when we double the size of the molecule and increase the basis set. But that's a question for another day. Right now, the goal is to get as much breadth as possible on the original question.
Notes on compiling NWChem
1. Boy were there some quirks with this one. First of all, although the instructions on the website give everything in terms of the CShell (remember csh? - big on Unix, not so big these days), you can just use the bash equivalents.
2. I wanted only single-CPU calculations so I tried to turn off MPI support. My first attempt "USE_MPI=n" caused build failures, and the only way to get around build failures appeared to be to delete the folder and untar the source again. Following the instructions on this post, I used "export ARMCI_NETWORK=SOCKETS" instead.
3. My favourite quirk was that when you untar the source, the generated folder has a really long name which causes a compile failure after some time as follows:
The directory name chosen for NWCHEM_TOP is longer than the maximum allowed value of 65 characters current NWCHEM_TOP=/home/noel/Tools/Quantum/nwchem-6.3.revision2-src.2013-10-17/srcRenaming to "nwchem" also failed (different error - can't find something or other I think). Renaming to "nwchem-6.3" worked.
4. I couldn't figure out how to get NWChem to use the system lapack library but got it to link to blas as described in the docs.