NWChem Known Bugs in version 3.3 and version 3.3.1

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# NWChem Known Bugs in version 3.3 It is recommended that users use the defaults in NWChem. They have been set to provide maximum efficiency for most users. If you feel you must change one of the defaults, be aware that you are responsible for ensuring that the results are correct. Below is a list of the known bugs in NWChem 3.3 and 3.3.1. If you believe that you have found bugs that are not listed here, please send your bug report using the correct channel listed in the Reporting Problems with NWChem page. Direct MP2 optimizations start, restart, and continue in the title CCSD(T) energies are unstable on the IBMSP Occasional restart file corruption in PREPARE module Possible problems with pgf77 Version 1.7 compiled binaries: especially using AUTOZ Slow parallel performance between Linux boxes Different number of iterations to find the total energy when using different number of processors on the Cray-T3E. Tabs are not working for input decks under Linux. Task shell is not working under Linux. QMD restarts are not working properly. CCSD(T) does not treat non-Abelian systems correctly. DFT BSSE calculations. Compile problem on Sun processors with workshop 4.2
Direct MP2 optimizations: MP2 optimizations that are performed with the direct option can have problems with CPHF convergence. In this case, the user is advised to use the default options which is a semi-direct calculation.
start, restart, and continue in the title: When the words start, restart, and continue appear at the beginning of the title, NWChem erroneously picks them up when scanning for start, restart, and continue directives. The work around is to not use these words in the title. This will be fixed in the next major release.
CCSD(T) energies are unstable on the IBMSP: CCSD(T) energies are unstable on the IBMSP using the LAPI version. The error that the user will see are jobs that just hang. We are working to solve this problem. This is improved in version 3.3.1, but may still occur.
Occasional restart file corruption in PREPARE module In some systems, when converting a restart file to a PDB file, the restart file gets corrupted. We are working to solve this problem. This is now fixed in version 3.3.1
Possible problems with pgf77 Version 1.7 compiled binaries: especially using AUTOZ We have tested with pgf77 Version 1.7 and have found that our automatic z-matrix code (AUTOZ in the GEOMETRY group) hangs but other functionality works. Since AUTOZ is the default, you will need to change the GEOMETRY group to contain NOAUTOZ. The pgf77 version has not been robustly tested and therefore, other problems may be encountered. Although we have not tested this, we have been told that pgf77 version 3.1 fixes this problem.
Slow parallel performance between Linux boxes With Linux kernels earlier than 2.2.x, there is a significant slow down when sending messages between Linux boxes. We have added some fixes to help alleviate this problem, but the best solution is to upgrade your kernel. There is also a kernel patch which helps to cut down latency in the TCP/IP socket based communication on the Linux clusters connected with Ethernet networks. We strongly recommend people to apply the patch to avoid communication performance problems.
Different number of iterations to find the total energy when using different number of processors on the Cray-T3E. This behavior can be seen when there are large numbers of degeneracies in the eigenvalues. So far we have not had a case that gives the wrong answer, but it may take a bit longer to get to the correct answer. This behavior in PEigS should be fixed for the next major release.
Tabs are not working for input decks under Linux. g77 effectively translates tabs into spaces. This is also true for character and Hollerith constants which we use to help us parse the tabs in an input deck. This results in problems with input decks that have tabs in them. Generally the error message shows up as:
    geom_input:center is neither atom nor bq       0
We hope to have this fixed in the next major release, but, in the meantime, get rid of the tabs in your input decks and everything should work fine.
Task shell is not working under Linux. This turns out to be a function of ARMCI catching a signal from the system call that "task shell" uses. This has been fixed for the next major release. If this functionality is needed before then, please contact nwchem-support@emsl.pnl.gov and request the fix.
QMD restarts are not working properly. Velocities are not saved for restarts so restarts of Quantum Molecular Dynamics (QMD) runs will not start with the correct velocities. This is fixed for the next major release. If this functionality is needed before then, please contact nwchem-support@emsl.pnl.gov and request the fix.
CCSD(T) does not treat non-Abelian systems correctly. There is a bug in the CCSD(T) code which may cause the code to give the error moints_trp: symmetry contamination: 2(2) when performing calculations on non-Abelian systems. The user should run this calculation with symmetry either turned off or in a proper Abelian subgroup.
DFT BSSE Calculation There is a bug in the DFT code which gives wrong results when ghost atoms are present. This has been fixed for the next release.
Compile problem on Sun processors with workshop 4.2 The user will get a fatal error when compiling nwchem/src/util/errquit.F that can be resolved by removing the -DJOBTIMEPATH definition in the makefile in the util directory. A better solution is to upgrade to at least workshop 5.0. NWChem | Capabilities | Platforms | Download | User's Manual | Programmer's Manual | Release Notes | FAQ Known Bugs | Support | Tutorial | Contributors | Benchmarks | Search | Mol Sci. Soft. Group | Citation Contact: NWChem Support Updated: March 8, 2005