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NWChem Known Bugs in version 4.1

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 4.1. 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.

  1. Compile problem on Sun processors with workshop 4.2
  2. Possible compile problems with True64 Compaq Fortran
  3. Direct MP2 optimizations
  4. Medium and large size calculation under Linux produce NaNs
  5. GM versions before 1.3 cause compilation errors
  6. ESPs give wrong results for spherical basis sets or UHF
  7. Computations requesting more than 4 GB of RAM per processor fail
  8. Build problem on Alpha Linux using Compaq compilers
  9. NWChem fails when nosegment is defined in combination with ECPs
  10. Geometry gets shifted when bqbq option is defined in geometry
  11. DFT fails with PGI compiler
  12. Wrong last DFT energy with decomp keyword
  13. Energy conservation in Car-Parrinello is not correct
  14. Unable to locate basis set libraries with Compaq Fortran compiler
  15. COSMO gives incorrect results
  16. Problem in PSPW with compiler optimization on SGI




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.


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.


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"


ESPs give incorrect results for spherical basis sets or UHF

The ESP module is restricted to use of cartesian basis sets, and for open shell systems to the use of restricted open shell Hartree-Fock (ROHF). This will either be fixed in the next release or error messages will be printed out and the job will stop.


Computations requesting more than 4 GB of RAM per processor fail

Important: this affect ONLY runs that use more than 4GB of RAM on each processor, runs that use an amount of aggregate memory (i.e. sum of all the RAM on each processor) larger than 4GB are not affected. This is a bug in the MA tool. A fix is available on request and will be available in the next release.


Build problem on Alpha Linux using Compaq compilers

There is a link problem in the ARMCI software for Alpha Linux using Compaq compilers. A fix is now in the download source file or a fix is available on request.


NWChem fails when nosegment is defined in combination with ECPs

When the nosegment option is defined in the basis set input, and and ECP is used, the code will fail with a message stating that it has an incorrect number of integrals. A fix is available on request.


Geometry gets shifted when bqbq option is defined in geometry

The molecular geometry gets shifted (this shift can be large) when the bqbq option has been specified in the geometry input. A fix is available on request.


DFT fails with PGI compiler

All DFT runs fail when the code is compiled with the Portland Group Fortran compiler. A fix is available on request.


Wrong last DFT energy with decomp keyword

If your DFT input file contains the decomp keyword, the last DFT Total Energy printed at the end of the SCF cycle is wrong, since the Correlation Energy is not included. A fix is available on request.


Energy conservation in Car-Parrinello is not correct

There is a fix available on request for this bug.


Unable to locate basis set libraries with Compaq Fortran compiler

NWChem is unable to obtain the libraries from the directory set via the NWCHEM_BASIS_LIBRARY environment variable or in .nwchemrc when compiled using the Compaq Fortran compiler. A fix is available on request


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.


Problem in PSPW with compiler optimization on SGI

There is a temporary solution to the problem that requires modifying a make file. Please e-mail NWChem Support for instructions on solving the problem.


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Updated: March 8, 2005