configure: error: fftw3 cannot be linked. Please define FFTW_HOME.

[Mylena Hail]

hello, I keep getting this error when doing the installation for lammps. i have tried export FFTW_HOME=[my path] as well as various alternatives but to no avail. any help would be greatly appreciated

[Xuanyu Zhu]

did not see your error. How does the config.log file look like?

[Xuanyu Zhu]

oh i understood the error message was in the title

[Xuanyu Zhu]

Another question if you can clarify: did this error happen when you compile MBX or compiling lammps? Assuming your error occurs during lammps compilation, here’s something you may attempt first: in the Makefile.mpi_mbx, add

LIB += $FFTW_HOME/lib/libfftw3f.a
LIB += $FFTW_HOME/lib/libfftw3.a

this may or may not work.

Sharing the config.log file will still be helpful.

[Jonatan Öström]

I also had problems with fftw. It doesn't seem like the configuration is able to find conda-installed fftw. The flag should point to the directory containing the lib/ and include/ directories containing fftw libs and headers. For example:

export FFTW_HOME=$CONDA_PREFIX

# or

export FFTW_HOME=/path/to/fftw-3.x.x

#then configure

./configure --enable-shared

make

make install

I think this flag and where it should point would be good to include in the README.md