[lammps-users] using the pppm features of LAMMPS - makefile problems and CCFLAGS

Hi all,
I am having some problems setting up a TIP4P water simulation, would appreciate some advice. When I try to run I get an error message that says: "cannot use ffts with FFT_NONE set". I have read the LAMMPS manual which seems to suggest that I need to download FFTW from fftw.org - which I have now done - and then change the makefile. Something appears to be going wrong here however as it now falls over when I try to 'make', which I think is to do with my editing of the makefile (to change where FFT_NONE is set). The original makefile we have been using - which is for a single linux based machine - is shown below. I tried changing "DFFT_NONE" to "DFFT_FFTW" which didn't work, and also adding "-lfftw" to the "USRLIB=" line which didn't help either. If anyone has any suggestions that would be great. Incidentally we don't use the poems or meam packages any more, but if I try removing these bits then it doesn't make.
Thanks in advance,

btw - I have not been able to search the mailing list archives in sourceforge for the past few days - anyone else having this problem?

# serial = RedHat Linux box, g++, no MPI, no FFTs

SHELL = /bin/sh

# System-specific settings

CC = g++
CCFLAGS = -g -O -I../STUBS -DFFT_NONE -I/home/Percy/Desktop/lammps/lib/poems
LINK = g++
LINKFLAGS = -g -O -L../STUBS -L/home/Percy/Desktop/lammps/lib/poems\
USRLIB = -lmpi -lpoems -lmeam -lgfortran
SIZE = size

# Link target

\(EXE\): (OBJ)
    \(LINK\) (LINKFLAGS) \(OBJ\) (USRLIB) \(SYSLIB\) \-o (EXE)
    \(SIZE\) (EXE)

# Library target

lib: \(OBJ\)     (ARCHIVE) \(ARFLAGS\) (EXE) $(OBJ)

# Compilation rules

    \(CC\) (CCFLAGS) -c $<

    \(CC\) (CCFLAGS) \(DEPFLAGS\) < > [email protected]

# Individual dependencies

DEPENDS = \(OBJ:\.o=\.d\) include (DEPENDS)

You need to be more specific: how does the build process fail? What is the
output of the "make" command?

You are on the right track, installing FFTW and specifying "-DFFT_FFTW" in
the Makefile together with the location of the library is the way to go.