Frequently Asked Questions¶

Installation¶

What is the oldxml?¶

The old format (-D__OLDXML) has been deprecated since version 6.4. oldxml allows you to read the output (wavefunctions, etc) from an old XML file.

How do I know when I need oldxml?¶

For newer version QE (>6.3), the XML file name is data-file-schema.xml. In contrast, the XML file name is data-file.xml for older version QE (some with precompiler flag -D__OLDXML)

Running¶

Some Intel MPI/MKL errors occur. What do I do?¶

Try:

export LD_PRELOAD=/opt/intel/mkl/lib/intel64/libmkl_rt.so

Why can’t I read the wavefunctions? Why does it hang?¶

If the wavefunctions were stored by old version QE (<6.4) or eQE, please try reinstall the QEpy with oldxml=yes.
There are two different ways to store wavefunctions in QE, which is controls by PW parameter wf_collect. In doubt, simply use one processor to read.

Some f90wrap errors occur. What do I do?¶

No module named f90wrap.__main__...

Please try install the latest f90wrap . e.g.
python -m pip install --upgrade f90wrap

Signal: Segmentation fault...¶

QEpy and mpi4py should installed with same compiler. If not, try reinstall the mpi4py by:
```
python -m pip install mpi4py --no-cache-dir
```

Bugs¶

GCC¶

For new version of gcc (eg. gcc=11.2) with LTO supported or under conda environment, if you met the problem when you install the QEpy:

lto1: fatal error:...

Try disable link-time-optimization by add -fno-lto to the variable FFLAGS and CFLAGS.

Gfortran¶

For gfortran>=10.0 sometimes still works, but will has error:

Type mismatch between actual argument...

Try to add -fallow-argument-mismatch to the variable FFLAGS (e.g. FFLAGS='-fPIC -fallow-argument-mismatch').

For some versions of the MacOS, maybe you will has error:

Illegal Instruction: 4...

Try to add -mmacosx-version-min=10.14 to the FFLAGS.

For a few versions of BLAS library, will raise error:

Segmentation fault - invalid memory reference...

This is due to the zdotc function of external libraries. More details to here. One solution is manually append the -Dzdotc=zdotc_wrapper to DFLAGS or MANUAL_DFLAGS in make.inc of QE. You also can do it during make:
make all MANUAL_DFLAGS='-Dzdotc=zdotc_wrapper'

Intel Compiler¶

If you met any problems like the following, please try a newer Intel compiler or GNU compiler.

[MPID_nem_tmi_pending_ssend_dequeue]: ERROR: can not find matching ssend...

The initial density totally wrong with more than one nodes.

The gcc version between 4.8-9.2 are supported by intel compiler, which upgraded until 2022.1 version. More details to here.

...error: attribute "__malloc__" does not take arguments...

OpenMPI¶

If you met some problems like the following:

mca_base_component_repository_open: unable to open mca_patcher_overwrite...

Please update to latest version of OpenMPI, or fix with patchelf (openmpi=2.1.1):
#!/bin/sh
prefix="/usr/lib/x86_64-linux-gnu/openmpi"
for filename in $(ls $prefix/lib/openmpi/*.so); do
    patchelf --add-needed libmpi.so.20 $filename
    patchelf --set-rpath "\$ORIGIN/.." $filename
done