# Project: ParallelCarParrinello
# Jan Hamaekers
# Frederik Heber
# 2005
#
# File: README

	ParallelCarParrinello

Is a mathematical-physical programme to calucate via density functional theory
the molecular (Car&Parrinello) dynamics of a many electron system, especially
the linear response of the system to a external magnetic field in a perturbation
approach in terms of susceptibility and chemical shielding. It was developed mainly
by Jan Hamaekers with additional code by Frederik Heber at the Institute for
Numerical Simulation at the University of Bonn[3].



INSTALLATION NOTES
==================

WINDOWS
-------
On a windows system the following packages will be needed under a cygwin environment: cygwin, mpi, perl, gcc

You need libfftw-2 from the fftw website[1] and also mpi[2], also you might need to compile both. MPI has to be in the path and know about its includes and libs (which it will most of the time)


LINUX
-----
If libfftw and alikes reside in a path which is not set via LD_... then use LDFLAGS ("-L/foo/bar/lib") and CFLAGS ("-I/foo/var/include") which are passed on to compiler and linker by (auto)make. After changing them you need to re-run configure. Also, if you receive error messages when launching such as "unable to finde shared object", try "ldd pcp" on the compiled executable. If a shared library cannot be found, you might want to add the path, where it resides, to the variable LD_LIBRARY_PATH.

If the executables spills out errors such as "error while loading shared libraries: libdrfftw.so.2:" because you cannot set the LD_LIBRARY_PATH on a distant node, then add the search path in the executable by adding to LDFLAGS 
LDFLAGS="... -Wl,-rpath,/path/to/fftw/lib"

LINKS
=====
[1] http://www.fftw.org/ - FFTW website
[2] http://www-unix.mcs.anl.gov/mpi/mpich/ - MPICH website
[3] http://www.ins.uni-bonn.de/