NWChem Known Bugs in version 4.5

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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. 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 Quantum molecular dynamics only works for SCF and DFT Problem with RHF GIAO calculations on TMS molecules using basis sets that contain d functions Problem in TI/PME evaulations Possible compile problems with True64 Compaq Fortran Medium and large size calculation under Linux produce NaNs 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. 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. Problem in TI/PME evaulations A fix will be available in the next release. 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: Change the f77 link to point to f77 instead of f90, 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 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 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