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<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 3.2 Final//EN">

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<H2><A ID="SECTION00033000000000000000">
2.3 <TT>configure</TT></A>
</H2>

<P>
To install the Q<SMALL>UANTUM </SMALL>ESPRESSO source package, run the <TT>configure</TT> script. This is actually a wrapper to the true <TT>configure</TT>,
located in the <TT>install/</TT> subdirectory (<TT>configure</TT> -h for help).
<TT>configure</TT> will (try to) detect compilers and libraries available on
your machine, and set up things accordingly. Presently it is expected
to work on all "common" computers, that is: based on Intel, AMD, ARM
CPUs, running Linux, Mac OS X, MS-Windows. Q<SMALL>UANTUM </SMALL>ESPRESSO is known go work on many
more kinds of machines but may requires some tweaking, especially for
the hardware of large HPC centers. Detailed but sometimes outdated 
installation instructions for specific HPC machines may be found in 
files <TT>install/README.</TT><EM>sys</EM>, where <EM>sys</EM> is the machine name.

<P>
Note: support for CMake is being added.

<P>
Instructions for the impatient:
<PRE>
    cd qe-X.Y.Z/
    ./configure
     make all
</PRE>
This will (try to) produce parallel (MPI) executable if a proper parallel
environment is detected, serial executables otherwise. For OpenMP executables,
specify <TT>./configure &ndash;enable-openmp</TT>. Symlinks to executable programs
will be placed in the <TT>bin/</TT>
subdirectory. Note that both C and Fortran compilers must be in your execution
path, as specified in the PATH environment variable.

<P>
<TT>configure</TT> generates the following files:

<P>
<TABLE CELLPADDING=3>
<TR><TD ALIGN="LEFT"><TT>make.inc</TT></TD>
<TD ALIGN="LEFT">compilation rules and flags (used by <TT>Makefile</TT>)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>install/configure.msg</TT></TD>
<TD ALIGN="LEFT">a report of the configuration run (not needed for compilation)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>install/config.log</TT></TD>
<TD ALIGN="LEFT">detailed log of the configuration run (useful for debugging)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>include/qe_cdefs.h</TT></TD>
<TD ALIGN="LEFT">(previously: <TT>include/c_defs.h</TT>)
	a few definitions used by C files</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>include/configure.h</TT></TD>
<TD ALIGN="LEFT">optionally: info on compilation flags
	(uncomment <code>#define __HAVE_CONFIG_INFO</code> 
	 in Modules/environment.f90 to enable its usage)</TD>
</TR>
</TABLE>
<BR>
NOTA BENE: if you interrupt <TT>make</TT>, it may fail when you start it again 
later (this will happen for instance if <TT>make</TT> is interrupted while unpacking
and compiling the FoX library). If so, run <TT>make clean</TT> before
running <TT>make</TT> again.
<BR>
NOTA BENE 1: it is convenient to use "parallel <TT>make</TT>" to speed up compilation:
<TT>make -jN</TT> compiles in parallel on N processors.
<BR>
NOTA BENE 2: <TT>configure</TT> no longer updates files <TT>make.depend</TT>,
containing dependencies upon modules, in the various subdirectories.
If you modify the sources, run <TT>./install/makedeps.sh</TT> or type
<TT>make depend</TT> to update files <TT>make.depend</TT>.
<BR>
NOTA BENE 3: <TT>make.inc</TT> used to be called <TT>make.sys</TT>
until v.6.0. The change of name is due to frequent problems with mailers
assuming that whatever ends in <TT>.sys</TT> is a suspect virus.

<P>
You should always be able to compile the Q<SMALL>UANTUM </SMALL>ESPRESSO suite
of programs without having to edit any of the generated files. However you
may have to tune <TT>configure</TT> by specifying appropriate environment variables
and/or command-line options. Usually the tricky part is to get external
libraries recognized and used: see Sec.<A HREF="node11.html#Sec:Libraries">2.4</A>
for details and hints.

<P>
Environment variables may be set in any of these ways:
<PRE>
     export VARIABLE=value; ./configure             # sh, bash, ksh
     setenv VARIABLE value; ./configure             # csh, tcsh
     env VARIABLE=value ./configure                 # any shell
     ./configure VARIABLE=value                     # any shell
</PRE>
As a rule: do not define environment variables for <TT>configure</TT> unless
you need it. Always try <TT>configure</TT> with no options as a first step.
Some environment variables that are relevant to <TT>configure</TT> are:

<P>
<TABLE CELLPADDING=3>
<TR><TD ALIGN="LEFT"><TT>ARCH</TT></TD>
<TD ALIGN="LEFT">label identifying the machine type (see below)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>F90, F77, CC</TT></TD>
<TD ALIGN="LEFT">names of Fortran, Fortran-77, and C compilers</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>MPIF90</TT></TD>
<TD ALIGN="LEFT">name of parallel Fortran 90 compiler (using MPI)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>CPP</TT></TD>
<TD ALIGN="LEFT">source file preprocessor (defaults to $CC -E)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>LD</TT></TD>
<TD ALIGN="LEFT">linker (defaults to $MPIF90)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>(C,F,F90,CPP,LD)FLAGS</TT></TD>
<TD ALIGN="LEFT">compilation/preprocessor/loader flags</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>LIBDIRS</TT></TD>
<TD ALIGN="LEFT">extra directories where to search for libraries</TD>
</TR>
</TABLE>
<BR>(note that <TT>F90</TT> is an ``historical'' name &ndash; we actually use
Fortran 2003 &ndash; and that it should be used only together with option
<TT>&ndash;disable-parallel</TT>. In fact, the value of F90 must be
consistent with the parallel Fortran compiler which is determined by 
<TT>configure</TT> and stored in the <TT>MPIF90</TT> variable).

<P>
For example, the following command line:
<PRE>
     ./configure MPIF90=mpif90 FFLAGS="-O2 -assume byterecl" \
                  CC=gcc CFLAGS=-O3 LDFLAGS=-static
</PRE>
instructs <TT>configure</TT> to use <TT>mpif90</TT> as Fortran compiler
with flags <TT>-O2 -assume byterecl</TT>, <TT>gcc</TT> as C compiler with
flags <TT>-O3</TT>, and to link with flag <TT>-static</TT>.
Note that the value of <TT>FFLAGS</TT> must be quoted, because it contains
spaces. NOTA BENE: passing the complete path to compilers (e.g.,
<TT>F90=/path/to/f90xyz</TT>) may lead to obscure errors during
compilation.

<P>
If your machine type is unknown to <TT>configure</TT>, you may use the
<TT>ARCH</TT>
variable to suggest an architecture among supported ones. Some large
parallel machines using a front-end (e.g. Cray XT) will actually
need it, or else <TT>configure</TT> will correctly recognize the front-end
but not the specialized compilation environment of those machines.
In some cases, cross-compilation requires to specify the target machine with the
<TT>&ndash;host</TT> option. This feature has not been extensively
tested, but we had at least one successful report (compilation
for NEC SX6 on a PC). Currently supported architectures are:

<P>
<TABLE CELLPADDING=3>
<TR><TD ALIGN="LEFT"><TT>x86_64</TT></TD>
<TD ALIGN="LEFT">Intel and AMD 64-bit running Linux</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>arm</TT></TD>
<TD ALIGN="LEFT">ARM machines (with gfortran or armflang)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>crayxt4</TT></TD>
<TD ALIGN="LEFT">Cray XT4/XT5/XE machines</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>mac686</TT></TD>
<TD ALIGN="LEFT">Apple Intel machines running Mac OS X</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>mingw32</TT></TD>
<TD ALIGN="LEFT">Cross-compilation for MS-Windows, using mingw, 32 bits</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>mingw64</TT></TD>
<TD ALIGN="LEFT">As above, 64 bits</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>cygwin</TT></TD>
<TD ALIGN="LEFT">MS-Windows PCs with Cygwin</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>ppc64</TT></TD>
<TD ALIGN="LEFT">Linux PowerPC machines, 64 bits</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>ppc64-mn</TT></TD>
<TD ALIGN="LEFT">as above, with IBM xlf compiler</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>ppc64-bg*</TT></TD>
<TD ALIGN="LEFT">IBM BlueGene</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>necsx*</TT></TD>
<TD ALIGN="LEFT">NEC SX-6 and SX-8 machines</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>ia32*</TT></TD>
<TD ALIGN="LEFT">Intel 32-bit machines (x86) running Linux</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>ia64*</TT></TD>
<TD ALIGN="LEFT">Intel 64-bit (Itanium) running Linux</TD>
</TR>
</TABLE>
<BR>
<P>
<EM>Note</EM>: <TT>x86_64</TT> replaces <TT>amd64</TT> since v.4.1.
Cray Unicos machines, SGI machines with MIPS architecture, HP-Compaq Alphas
are no longer supported since v.4.2; PowerPC Macs are no longer
supported since v.5.0; IBM machines with AIX are no longer supported
since v.6.0. Architectures marked with a * are to be considered obsolescent
or obsolete.

<P>
Finally, <TT>configure</TT> recognizes the following command-line options:
<BR><TABLE CELLPADDING=3>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-parallel</TT></TD>
<TD ALIGN="LEFT">compile for parallel (MPI) execution if possible (default: yes)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-openmp</TT></TD>
<TD ALIGN="LEFT">compile for OpenMP execution if possible (default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-shared</TT></TD>
<TD ALIGN="LEFT">use shared libraries if available (default: yes;</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">"no" is implemented, untested, in only a few cases)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-debug</TT></TD>
<TD ALIGN="LEFT">compile with debug flags (only for some compilers; default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-pedantic</TT></TD>
<TD ALIGN="LEFT">compile with pedantic flags (only for gfortran; default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-signals</TT></TD>
<TD ALIGN="LEFT">enable signal trapping (default: disabled)</TD>
</TR>
</TABLE>
<BR>
<BR>
and the following optional packages:
<BR><TABLE CELLPADDING=3>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-scalapack</TT></TD>
<TD ALIGN="LEFT">(yes|no|intel) Use scalapack if available.</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">Set to <TT>intel</TT> to use Intel MPI and blacs (default: use OpenMPI)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-elpa-include</TT></TD>
<TD ALIGN="LEFT">Specify full path of ELPA include and modules
  headers (default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-elpa-lib</TT></TD>
<TD ALIGN="LEFT">Specify full path of the ELPA library
	                          (default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-elpa-version</TT></TD>
<TD ALIGN="LEFT">Specify ELPA version, only year (2015 or 2016,
	                          default: 2016)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-hdf5</TT></TD>
<TD ALIGN="LEFT">(no | | yes | <TT>&lt;path&gt;</TT>)</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">Use HDF5, if yes configure assumes</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">that a valid installation with version &gt;= 1.8.16 is</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">available, and h5cc and h5fc are in the default</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">executable search path; &lt;path&gt; must be the root</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">folder of a standalone hdf5 installation. (default: no).</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-hdf5-libs=</TT></TD>
<TD ALIGN="LEFT">Specify the linker options needed by HDF5 when</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">configure fails to detect them by itself. As value</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">to specify here is usually composed by many</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">substrings it should be enclosed by quotes so to</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">prevent configure failures. (default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-hdf5-include</TT></TD>
<TD ALIGN="LEFT">Specify full path the HDF5 include folder containing</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">module and headers files. Use it if configure fails</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">to detect the path by itself. (default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-libxc</TT></TD>
<TD ALIGN="LEFT">Link the <TT>libxc</TT> library (default:no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-libxc-prefix</TT></TD>
<TD ALIGN="LEFT">directory where <TT>libxc</TT> is installed</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-libxc-include</TT></TD>
<TD ALIGN="LEFT">directory where <TT>libxc</TT> Fortran headers reside</TD>
</TR>
</TABLE>
<BR>
<BR>
The following options are available for the CUDA Fortran GPU version:
<BR><TABLE CELLPADDING=3>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-cuda=value</TT></TD>
<TD ALIGN="LEFT">enables compilation of the CUDA Fortran</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">accelerated subroutines.</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT"><TT>value</TT> should point the path where the CUDA toolkit</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">is installed, e.g. <TT>/opt/cuda</TT> (default: no)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-cuda-cc=value</TT></TD>
<TD ALIGN="LEFT">sets the compute capabilities for the compilation</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">of the accelerated subroutines.</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT"><TT>value</TT> must be consistent with the hardware and the</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">NVidia driver installed on the workstation or on the</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">compute nodes of the HPC facility (default: 35)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;with-cuda-runtime=value</TT></TD>
<TD ALIGN="LEFT">sets the version of the CUDA toolkit used</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">for the compilation of the accelerated code.</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT"><TT>value</TT> must be consistent with the</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">CUDA Toolkit installed on the workstation</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">or available on the compute nodes of the HPC facility.</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">PGI compilers currently accept 7.5, 8.0 or 9.0 (default: 8.0)</TD>
</TR>
<TR><TD ALIGN="LEFT"><TT>&ndash;enable-cuda-env-check=[yes]</TT></TD>
<TD ALIGN="LEFT">if set, sanity checks on the CUDA environment</TD>
</TR>
<TR><TD ALIGN="LEFT"> </TD>
<TD ALIGN="LEFT">are performed (default: yes).</TD>
</TR>
</TABLE>
<BR>
<P>
Please remember that in order to compile the CUDA code for GPU's you need ... 
the CUDA code (it is aligned to but separated from the main distribution)! 
you also need a recent version of the PGI Fortran compiler. 
OpenMP must be enabled,
and you may want to use a CUDA-aware MPI distribution to optimize the data
transfer between the processes.

<P>
If you want to modify <TT>configure</TT> (advanced users only!),
see the Wiki pages on GitLab.

<P>

<H3><A ID="SECTION00033100000000000000"></A>
<A ID="SubSec:manconf"></A>
<BR>
2.3.1 Manual configuration
</H3>
If <TT>configure</TT> stops before the end, and you don't find a way to fix
it, you have to write a working <TT>make.inc</TT> file (optionally,
<TT>include/qe_cdefs.h</TT>). The template used by <TT>configure</TT> is
<TT>install/make.inc.in</TT> and contains explanations of the meaning
of the various variables. Note that you may need
to select appropriate preprocessing flags
in conjunction with the desired or available
libraries (e.g. you need to add <TT>-D__FFTW</TT> to <TT>DFLAGS</TT>
if you want to link internal FFTW). For a correct choice of preprocessing
flags, refer to the documentation in <TT>include/defs.h.README</TT>.

<P>
NOTA BENE: If you change any settings (e.g. preprocessing,
compilation flags)
after a previous (successful or failed) compilation, you must run
<TT>make clean</TT> before recompiling, unless you know exactly which
routines are affected by the changed settings and how to force their
recompilation. <TT>configure</TT> will clean objects and executables, unless
you use option <TT>&ndash;save</TT>.

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