!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CONTENTS
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! QEdark
Code to evaluate and integrate the form factor as in eq (3.16) in Essig et.al. -- arXiV:1509.01598 and integrals of this quantity in order to calculate the DM-electron scattering rate.
QEdark calculation modes:
calculation_mode='f2' gives eq. (4.4) as the output quantity.
calculation_mode='multimass' computes the crystal form factor multiplied by the weight eta(vmin(Ei, Ei')), giving an output quantity that is proportional to the scattering rate.
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IMPORTANTQEdark is an extension to the PWscf code of the Quantum ESPRESSO package. It has been written to work with QE version v.5.1.2. It may work with other versions but this is not guranteed.
We greatly acknowledge the Quantum ESPRESSO team for making their code community accessible. See the following publication for details P. Giannozzi et.al. J. Phys. Condens. Matter 21, 395502 (2009)
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QEdark QUICK INSTALLATION GUIDE1) Download QuantumESPRESSO v.5.1.2 from www.qe-forge.org/gf/download/frsrelease/185/753/espresso-5.1.2.tar.gz
2) Modify pwscf.f90 by including the code line call qedark() just above the line CALL stop_run( exit_status )
3) Modify PW/src/Makefile to include dependencies on two new files. Simply add
qedark.o \
qedark_routines.o \
qedark_f2.o \
qedark_multimass.o \
qedark_read_input.o \
directly below
wyckoff.o \4) Copy the files qedark.f90, qedark_routines.f90, qedark_f2.f90 and qedark_multimass.f90 from QEdark_files into Quantum ESPRESSO's directory PW/src/
5) Run configure script in QE main directory as ./configure --disable-parallel
For OpenMP multithreaded version, run configure as
./configure --disable-parallel --enable-openmp
NOTE:QEdark v1.0 does not support OpenMPI parallelization6) Compile by typing the following command in QE main directory make pw
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QEdark QUICK EXECUTION GUIDELINES1) The file dm.in must exist in the directory where the code is being run since it contains the input data to QEdark.
2) QEdark is executed within Quantum ESPRESSO's pw.x program which is copied to the bin/ directory. Execute as QEdark_dir/bin/pw.x < QEinputfile > QEoutputfile
3) In order to run the multithreaded version, the value of OMP_STACKSIZE will most likely need to be increased. For Si and Ge we have found that setting it to 512M has been enough.
In bash this can be done by entering the commmand
export OMP_STACKSIZE=512M 4) Users are encouraged to get familiar with the code by going through the examples in the folder QEdark_examples/, which have been chosen to introduce the user into several features of QEdark.
5) Previous knowledge of Quantum ESPRESSO is highly recommended. There are plenty of tutorials and examples at the link http://www.quantum-espresso.org/tutorials/
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TO-DO
1) Make code more modular. In particular, split into one routine
to evaluate the form factors and another external
routine to carry out the momentum space integrals and
sum over bands
2) Eliminate all the G-vector index tables by
understanding the G-vector sorting -- BYPASSED BY REDIFINING q-grid
3) Make this calculation an external program to pw.x
4) Parallelize with MPI
5) IMPROVE CODE COMMENTS!!!! In particular explain the algorithm for
selecting the G-vectors, and the reason why the array index is needed
6) Rearrange create_bins so that unnecessary variables don't need to be passed
depending on the case. Also, put the whole binning stuff into a module, so
that allocatable arrays can be passed. This way we can allocate binedges(:)
inside create_bins() instead of in formfact() (which is already too cluttered!)!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!