C and Fortran compilers must be in your PATH. If configure says that you have no working compiler, well, you have no working compiler, at least not in your PATH, and not among those recognized by configure.
Instead, if you want to compile a native version of QE, you just need to add the -mmic flag and cross compile. If you want to use the symmetric mode, you need to compile twice: with and without the -mmic flag". "[...] everything, i.e. code+libraries, must be cross-compiled with the -mmic flag. In my opinion, it's pretty unlikely that native mode can outperform the execution on the standard Xeon cpu. I strongly suggest to use the Xeon Phi in offload mode, for now" (info by Fabio Affinito, March 2015).
(This section is likely obsolete)
For Cray XE machines:
$ module swap PrgEnv-cray PrgEnv-pgi $ ./configure --enable-openmp --enable-parallel --with-scalapack $ vim make.incthen manually add -D__IOTK_WORKAROUND1 at the end of DFLAGS line.
''Now, despite what people can imagine, every CRAY machine deployed can have different environment. For example on the machine I usually use for tests [...] I do have to unload some modules to make QE running properly. On another CRAY [...] there is also Intel compiler as option and the system is slightly different compared to the other. So my recipe should work, 99% of the cases.'' (info by Filippo Spiga)
For Cray XT machines, use ./configure ARCH=crayxt4 or else configure will not recognize the Cray-specific software environment.
Older Cray machines: T3D, T3E, X1, are no longer supported.
The current configure was working on the machines at CINECA and at Jülich. For other machines, you may need something like
./configure ARCH=ppc64-bg BLAS_LIBS=... LAPACK_LIBS=... \ SCALAPACK_DIR=... BLACS_DIR=..."where the various *_LIBS and *_DIR "suggest" where the various libraries are located.
Both AMD and Intel CPUs, 32-bit and 64-bit, are supported and work, either in 32-bit emulation and in 64-bit mode. 64-bit executables can address a much larger memory space than 32-bit executable, but there is no gain in speed. Beware: the default integer type for 64-bit machine is typically 32-bit long. You should be able to use 64-bit integers as well, but it is not guaranteed to work and will not give any advantage anyway.
Currently, configure supports Intel (ifort), NAG (nagfor), PGI (pgf90) and gfortran compilers. Pathscale, Sun Studio, AMD Open64, are no longer supported after v.6.2: g95, since v.6.1.
Both Intel MKL and AMD acml mathematical libraries are supported, the former much better than the latter.
It is usually convenient to create semi-statically linked executables (with only libc, libm, libpthread dynamically linked). If you want to produce a binary that runs on different machines, compile it on the oldest machine you have (i.e. the one with the oldest version of the operating system).
You need at least gfortran v.4.4 or later to properly compile QUANTUM ESPRESSO.
"There is a known incompatibility problem between the calling convention for Fortran functions that return complex values: there is the convention used by g77/f2c, where in practice the compiler converts such functions to subroutines with a further parameter for the return value; gfortran instead produces a normal function returning a complex value. If your system libraries were compiled using g77 (which may happen for system-provided libraries in not-too-recent Linux distributions), and you instead use gfortran to compile QUANTUM ESPRESSO, your code may crash or produce random results. This typically happens during calls to zdotc, which is one the most commonly used complex-returning functions of BLAS+LAPACK.
For further details see for instance this link:
http://www.macresearch.org/lapackblas-fortran-106#comment-17071
or read the man page of gfortran under the flag -ff2c.
If your code crashes during a call to zdotc, try to recompile QUANTUM ESPRESSO using the internal BLAS and LAPACK routines (using the -with-internal-blas and -with-internal-lapack parameters of the configure script) to see if the problem disappears; or, add the -ff2c flag" (info by Giovanni Pizzi, Jan. 2013).
Note that a similar problem with complex functions exists with MKL libraries as well: if you compile with gfortran, link -lmkl_gf_lp64, not -lmkl_intel_lp64, and the like for other architectures. Since v.5.1, you may use the following workaround: add preprocessing option -Dzdotc=zdotc_wrapper to DFLAGS.
The Intel compiler ifort http://software.intel.com/ produces fast executables, at least on Intel CPUs, but not all versions work as expected (see below). In case of trouble, update your version with the most recent patches. Since each major release of ifort differs a lot from the previous one, compiled objects from different releases may be incompatible and should not be mixed.
The Intel compiler is no longer free for personal usage, but it is still for students and open-source contributors (https://software.intel.com/en-us/qualify-for-free-software).
If configure doesn't find the compiler, or if you get Error loading shared libraries at run time, you may have forgotten to execute the script that sets up the correct PATH and library path. Unless your system manager has done this for you, you should execute the appropriate script - located in the directory containing the compiler executable - in your initialization files. Consult the documentation provided by Intel.
The warning: feupdateenv is not implemented and will always fail, can be safely ignored. Warnings on ``bad preprocessing option'' when compiling iotk and complains about ``recommended formats'' may also be ignored.
The following compiler releases are known to give segmentation faults in at least some cases of compilation of QUANTUM ESPRESSO v.6.0:
12.0.0.084 Build 20101006(Filippo Spiga, Aug. 2016)
12.0.1.107 Build 20101116
12.0.2.137 Build 20110112
12.0.4.191 Build 20110427
12.0.5.220 Build 20110719
16.0.1.150 Build 20151021
ifort v.12: release 12.0.0 miscompiles iotk, leading to mysterious errors when reading data files. Workaround: increase the parameter BLOCKSIZE to e.g. 131072*1024 when opening files in iotk/src/iotk_files.f90 (info by Lorenzo Paulatto, Nov. 2010).
ifort v.11: Segmentation faults were reported for the combination ifort 11.0.081, MKL 10.1.1.019, OpenMP 1.3.3. The problem disappeared with ifort 11.1.056 and MKL 10.2.2.025 (Carlo Nervi, Oct. 2009).
configure should recognize properly installed MKL libraries.
By default the non-threaded version of MKL is linked, unless option
configure -with-openmp is specified. In case of trouble,
refer to the following web page to find the correct way to link MKL:
http://software.intel.com/en-us/articles/intel-mkl-link-line-advisor/.
For parallel (MPI) execution on multiprocessor (SMP) machines, set the
environment variable OMP_NUM_THREADS to 1 unless you know what you
are doing. See Sec. for more info on this
and on the difference between MPI and OpenMP parallelization.
If you get a mysterious "too many communicators" error and a
subsequent crash: there is a bug in Intel MPI and MKL 2016 update 3.
See this thread and the links quoted therein:
http://www.mail-archive.com/pw_forum@pwscf.org/msg29684.html
.
Apart from such problems, QUANTUM ESPRESSO compiles and works on all non-buggy, properly configured hardware and software combinations. In some cases you may have to recompile MPI libraries: not all MPI installations contain support for the Fortran compiler of your choice (or for any Fortran compiler at all!).
If QUANTUM ESPRESSO does not work for some reason on a PC cluster,
try first if it works in serial execution. A frequent problem with parallel
execution is that QUANTUM ESPRESSO does not read from standard input,
due to the configuration of MPI libraries: see Sec..
If you are dissatisfied with the performances in parallel execution,
see Sec.
and in particular Sec.
.
Another option is Cygwin, a UNIX environment which runs under Windows: see
http://www.cygwin.com/.
Finally, Windows-10 users may enable the Windows Subsystem for Linux and install there a Linux distribution.
Mac OS-X machines (10.4 and later) with Intel CPUs are supported by configure, both with gfortran and with the Intel compiler ifort and MKL libraries. Parallel compilation with OpenMPI also works.
Gfortran information and binaries for Mac OS-X here: http://hpc.sourceforge.net/ and https://wiki.helsinki.fi/display/HUGG/GNU+compiler+install+on+Mac+OS+X.
Mysterious crashes, occurring when zdotc is called, are due to the same incompatibility of complex functions with some optimized BLAS as reported in the "Linux PCs with gfortran" paragraph. Workaround: add preprocessing option -Dzdotc=zdotc_wrapper to DFLAGS.