qmcpack/README

1. Getting and building QMCPACK

Obtain the latest release or development copy from http://www.qmcpack.org

2. Prerequisites

* C/C++ compilers
* CMake, build utility, http://www.cmake.org
* BLAS/LAPACK, numerical library, use platform-optimized libraries
* Libxml2, XML parser, http://xmlsoft.org/ 
* HDF5, portable I/O library, http://www.hdfgroup.org/HDF5/
* BOOST, peer-reviewed portable C++ source libraries, http://www.boost.org
* FFTW, FFT library, http://www.fftw.org/

Note that the einspline library is no longer required.

3. Building with cmake

The build system for QMCPACK is based on CMake.  It will autoconfigure
based on the detected compilers and libraries. Previously QMCPACK made
extensive use of toolchains, but the system has since been updated to
eliminate the use of toolchain files for most cases.  The build
system works with GNU, Intel, and IBM XLC compilers.  Specific compile options
can be specified either through specific environmental or CMake
variables.  When the libraries are installed in standard locations,
e.g., /usr, /usr/local, there is no need to set environmental or cmake
variables for the packages.

See http://docs.qmcpack.org for build examples on Linux, Mac OS X etc.

3.1. Quick build

If you are feeling lucky and are on a standard UNIX-like system such
as a Linux workstation:

* Safest quick build option is to specify the C and C++ compilers
  through their MPI wrappers. Here we use Intel MPI and Intel
  compilers. Move to the build directory, run cmake and make

  cd build
  cmake -DCMAKE_C_COMPILER=mpiicc -DCMAKE_CXX_COMPILER=mpiicpc ..
  make -j 8

* Substitute mpicc and mpicxx or other wrapped compiler names to suit
  your system. e.g. With OpenMPI use

  cd build
  cmake -DCMAKE_C_COMPILER=mpicc -DCMAKE_CXX_COMPILER=mpicxx ..
  make -j 8

* If you are feeling particularly lucky, you can skip the compiler
  specification:

  cd build
  cmake ..
  make -j 8

The complexities of modern computer hardware and software systems are
such that you should check that the autoconfiguration system has made
good choices and picked optimized libraries and compiler settings
before doing significant production. i.e. Check the details below.

3.2. Set the environment

A number of enviornmental variables affect the build.  In particular
they can control the default paths for libraries, the default
compilers, etc.  The list of enviornmental variables is given below:

   CXX              C++ compiler
   CC               C Compiler
   MKL_HOME         Path for MKL
   LIBXML2_HOME     Path for libxml2
   HDF5_ROOT        Path for HDF5
   BOOST_ROOT       Path for Boost
   FFTW_HOME        Path for FFTW

3.3. CMake options

In addition to reading the enviornmental variables, CMake provides a
number of optional variables that can be set to control the build and
configure steps.  When passed to CMake, these variables will take
precident over the enviornmental and default variables.  To set them
add -D FLAG=VALUE to the configure line between the cmake command and
the path to the source directory.

  * General build options
    CMAKE_BUILD_TYPE    A variable which controls the type of build (defaults to Release).  Possible values are:
                        None (Do not set debug/optmize flags, use CMAKE_C_FLAGS or CMAKE_CXX_FLAGS)
                        Debug (create a debug build)
                        Release (create a release/optimized build)
                        RelWithDebInfo (create a release/optimized build with debug info)
                        MinSizeRel (create an executable optimized for size)
    CMAKE_C_COMPILER    Set the C compiler
    CMAKE_CXX_COMPILER  Set the C++ compiler
    CMAKE_C_FLAGS       Set the C flags.  Note: to prevent default debug/release flags from being used, set the CMAKE_BUILD_TYPE=None
                        Also supported: CMAKE_C_FLAGS_DEBUG, CMAKE_C_FLAGS_RELEASE, CMAKE_C_FLAGS_RELWITHDEBINFO
    CMAKE_CXX_FLAGS     Set the C++ flags.  Note: to prevent default debug/release flags from being used, set the CMAKE_BUILD_TYPE=None
                        Also supported: CMAKE_CXX_FLAGS_DEBUG, CMAKE_CXX_FLAGS_RELEASE, CMAKE_CXX_FLAGS_RELWITHDEBINFO

  * Key QMC build options
    QMC_CUDA            Enable CUDA and GPU acceleration (1:yes, 0:no)
    QMC_COMPLEX         Build the complex (general twist/k-point) version (1:yes, 0:no)
    
  * Additional QMC options
    QMC_DATA            Specify data directory for QMCPACK (currently unused, but likely to be used for performance tests)
    QMC_INCLUDE         Add extra include paths
    QMC_EXTRA_LIBS      Add extra link libraries
    QMC_BUILD_STATIC    Add -static flags to build
    
  * libxml
    Libxml2_INCLUDE_DIRS  Specify include directories for libxml2
    Libxml2_LIBRARY_DIRS  Specify library directories for libxml2

  * FFTW
    FFTW_INCLUDE_DIRS   Specify include directories for FFTW
    FFTW_LIBRARY_DIRS   Specify library directories for FFTW

3.4. Configure and build

* Move to build directory, run cmake and make

   cd build
   cmake ..
   make -j 8

3.5. Example configure and build

* Set the environments (the examples below assume bash, Intel compilers and MKL library)

  export CXX=icpc
  export CC=icc
  export MKL_HOME=/usr/local/intel/mkl/10.0.3.020
  export LIBXML2_HOME=/usr/local
  export HDF5_ROOT=/usr/local
  export BOOST_ROOT=/usr/local/boost
  export FFTW_HOME=/usr/local/fftw

* Move to build directory, run cmake and make

  cd build
  cmake -D CMAKE_BUILD_TYPE=Release ..
  make -j 8

3.6.  Special notes

It is recommended to create a helper script that contains the
configure line for CMake.  This is particularly useful when avoiding
enviornmental variables, packages are installed in custom locations,
or the configure line may be long or complex.  In this case it is
recommended to add "rm -rf CMake*" before the configure line to remove
existing CMake configure files to ensure a fresh configure each time
that the script is called.  and example script build.sh is given
below:

   export CXX=mpic++
   export CC=mpicc
   export ACML_HOME=/opt/acml-5.3.1/gfortran64
   export HDF5_ROOT=/opt/hdf5
   export BOOST_ROOT=/opt/boost

   rm -rf CMake*

   cmake                                                \
      -D CMAKE_BUILD_TYPE=Debug                         \
      -D Libxml2_INCLUDE_DIRS=/usr/include/libxml2      \
      -D Libxml2_LIBRARY_DIRS=/usr/lib/x86_64-linux-gnu \
      -D FFTW_INCLUDE_DIRS=/usr/include                 \
      -D FFTW_LIBRARY_DIRS=/usr/lib/x86_64-linux-gnu    \
      -D QMC_EXTRA_LIBS="-ldl ${ACML_HOME}/lib/libacml.a -lgfortran" \
      -D QMC_DATA=/projects/QMCPACK/qmc-data            \
      ..


3.7.  Additional examples:
QMCPACK includes validation tests to ensure the correctness of the
code, compilers, tools, and runtime. The tests should ideally be run
each compilation, and certainly before any research use. The tests
check the output against known mean-field, quantum chemistry, and
other QMC results.

Set compile flags manually:
   cmake                                                \
      -D CMAKE_BUILD_TYPE=None                          \
      -D CMAKE_C_COMPILER=mpicc                         \
      -D CMAKE_CXX_COMPILER=mpic++                      \
      -D CMAKE_C_FLAGS="  -O3 -fopenmp -malign-double -fomit-frame-pointer -finline-limit=1000 -fstrict-aliasing -funroll-all-loops -Wno-deprecated -march=native -mtune=native" \
      -D CMAKE_CXX_FLAGS="-O3 -fopenmp -malign-double -fomit-frame-pointer -finline-limit=1000 -fstrict-aliasing -funroll-all-loops -Wno-deprecated -march=native -mtune=native" \
      ..

Add extra include directories:
   cmake                                                \
      -D CMAKE_BUILD_TYPE=Release                       \
      -D CMAKE_C_COMPILER=mpicc                         \
      -D CMAKE_CXX_COMPILER=mpic++                      \
      -D QMC_INCLUDE="~/path1;~/path2"                  \
      ..


4. Testing and validation of QMCPACK

For more informaton, consult QMCPACK pages at http://www.qmcpack.org and http://docs.qmcpack.org
The tests currently use up to 16 cores in various combinations of MPI
tasks and OpenMP threads. 

Note that due to the small electron and walker counts used in the
tests, they should not be used for any performance measurements. These
should be made on problem sizes that are representative of actual
research calculations.

4.1 Run the short (quick) tests

* From the build directory, invoke ctest specifying only tests
  including "short" should be run

  ctest -R short

These tests currently take several minutes to run. All tests should pass.

4.2 Run the long verification tests

For greater surety, the long verification tests use a far greater
number of statistical samples than the "short" tests. These take
several hours each to run.

* From the build directory, invoke ctest with an increased test timeout

  ctest --timeout 36000

This will run all the defined tests, "short" and "long". If you are
running on a system such as a large shared supercomputer you will
likely have to run these tests from inside a submitted job to avoid
run length limits.

4.3 Run individual tests

Individual tests can be run by specifying their name

  ctest -R name-of-test-to-run


5. Documentation and support

For more informaton, consult QMCPACK pages at http://www.qmcpack.org
and http://docs.qmcpack.org

If you have trouble building or using QMCPACK, please post to the
Google QMCPACK group or contact a developer.