[gmx-users] Code precision is double message

[Mark Abraham]

On 18/06/2012 4:30 PM, Allen Mao wrote:
> So getting an error message when tying to run an MD simulation created in
> 4.0.5 on 4.5.5
>
> These are the steps I followed, and help would be appreciated
> untared FFTW-3.3.1
> ./configure --enable-threads --enable-float --prefix=$home/fftw-3.3.1
> make
> make install
> untared gromacs-4.5.5
> export CPPFLAGS="-I$home/fftw-3.3.1/include/"
> export LDFLAGS="-L$home/fftw-3.3.1/lib"
> ./configure --prefix=$home/gromacs-4.5.5 --disable-shared
> make
> make install
>
> No issues up to this point, no error message or anything.
> When I try to run the following
> $home/gromacs-4.5.5/bin/mdrun -s md_11.tpr -cpi md_10.cpt -cpo md_11.cpt
>
> I get the following error message
> -------------------------------------------------------
> Program mdrun, VERSION 4.5.5
> Source code file: checkpoint.c, line: 546
>
> Fatal error:
> Precision mismatch for state entry nosehoover-xi, code precision is double,
> file precision is float
>
> For more information and tips for troubleshooting, please check the GROMACS
> website at http://www.gromacs.org/Documentation/Errors
> -------------------------------------------------------

Apparently the checkpoint file format in version 4.0.5 cannot be read 
properly by 4.5.5. Since the algorithms are slightly different in each 
GROMACS version, you don't want to do this anyway. Start a new simulation.

Mark