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NWChem Known Bugs in version 4.5

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 4.5 beta. 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.

  1. Direct MP2 optimizations
  2. COSMO gives incorrect results
  3. Quantum molecular dynamics only works for SCF and DFT
  4. Problem with RHF GIAO calculations on TMS molecules using basis sets that contain d functions
  5. SCF lock directive broken in parallel runs
  6. Problem in TI/PME evaulations
  7. Compile problem on Sun processors with workshop 4.2
  8. Possible compile problems with True64 Compaq Fortran
  9. Medium and large size calculation under Linux produce NaNs
  10. GM versions before 1.3 cause compilation errors




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.


COSMO gives incorrect results

The COSMO model will give incorrect results for the solvation energy. In addition one of the options necessary has not been defined in the user manual. In order to obtain the same results as the NWChem 4.0.1 version the user should define the following parameters in the cosmo input block:

ifscrn 2
iscren 0

The problem will be resolved in the next release of NWChem.


Quantum molecular dynamics only works for SCF and DFT

A fix is now available upon request from nwchem-support@emsl.pnl.gov.


Problem with RHF GIAO calculations on TMS molecules using basis sets that contain d functions

A fix will be available in the next release.


SCF lock directive broken in parallel runs

A fix will be available in the next release.


Problem in TI/PME evaulations

A fix will be available in 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 GNUmakefile in the util directory. A better solution is to upgrade to at least workshop 5.0.


Possible compile problems with True64 Compaq Fortran

Some versions of True64 Compaq Fortran default f77 to point to f90 and the compile will break because of problems with cpp and f90. This has been reported for V5.3-915. There are three known solutions:

  1. Change the f77 link to point to f77 instead of f90,
  2. Add the flag -old_f77 as the first flag in the FC definition of the DECOSF section of the $NWCHEM_TOP/src/config/makefile.h file, or
  3. Upgrade to version X5.3-1155 plus the patches at http://www6.compaq.com/fortran/dfau.html#updates.


Medium and large size calculation under Linux produce NaNs

2.2 Linux kernels are known to produce random wrong floating point arithmetic (eventually causing NaNs), see for example:

http://www.ccl.net/cgi-bin/ccl/message.cgi?2000+06+06+002
http://www.ccl.net/cgi-bin/ccl/message.cgi?2001+02+23+012
BUG: Global FPU corruption in 2.2
Re: BUG: Global FPU corruption in 2.2

We have experienced the same problems running NWChem with a 2.2.x kernel. This is likely due to FPU problems that has been fixed in kernel 2.2.20 and in the 2.4 series.

To fix the problem, we strongly suggest you to install 2.4.x kernels available at

http://www.kernel.org/pub/linux/kernel/v2.4/

or to upgrade your 2.2 kernel to version 2.2.20, whose source is available at

http://www.kernel.org/pub/linux/kernel/v2.2/linux-2.2.20.tar.gz


GM versions before 1.3 cause compilation errors

If you are using a version of GM more recent than 1.3, you are going to experience a compilation error, to avoid this you need to edit $NWCHEM_TOP/src/tools/armci/src/myrinet.c adding this line

#define GM_STRONG_TYPES 0

just before

#include "gm.h"


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Created by Theresa Windus
Updated : Fri Apr 11 14:44:19 PDT 2003