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Contents
Contents
User's Guide for Q
UANTUM
ESPRESSO
(version 4.1.1)
Contents
1 Introduction
1.1 What can Q
UANTUM
ESPRESSO do
1.2 People
1.3 Contacts
1.4 Terms of use
2 Installing Q
UANTUM
ESPRESSO
2.1 Download
2.2 Installation
2.3
configure
2.3.1 Libraries
2.3.1.1 BLAS and LAPACK
2.3.1.2 FFT
2.3.1.3 MPI libraries
2.3.1.4 Other libraries
2.3.2 Manual configuration
2.4 Compilation
2.4.0.1 Other utilities
2.5 Running examples
2.6 Installation tricks and problems
2.6.1 All architectures
2.6.2 IBM AIX
2.6.3 Linux PC
2.6.3.1 Linux PCs with Portland Group compiler (pgf90)
2.6.3.2 Linux PCs with Pathscale compiler
2.6.3.3 Linux PCs with gfortran
2.6.3.4 Linux PCs with Intel compiler (ifort, formerly ifc)
2.6.3.5 Linux PCs with MKL libraries
2.6.3.6 Fun with precompiled libraries
2.6.4 AMD 32-bit CPUs
2.6.5 64-bit CPUs
2.6.6 Linux PC clusters with MPI
2.6.7 Intel Mac OS X
2.6.7.1 Intel Mac OS X with ifort
2.6.7.2 Intel Mac OS X 10.4 and 10.5 with g95 and gfortran
3 Parallelism
3.1 Understanding Parallelism in Q
UANTUM
ESPRESSO
3.2 Running on parallel machines
3.3 Parallelization levels in Q
UANTUM
ESPRESSO
3.3.0.1 Massively parallel calculations
3.3.1 Understanding parallel I/O
3.3.1.1 Cray XT3
3.4 Tricks and problems
3.4.0.1 Trouble with input files
3.4.0.2 Trouble with MKL and MPI parallelization
3.4.0.3 Trouble with compilers and MPI libraries
4 Using PWscf
4.1 Electronic and ionic structure calculations
4.1.0.1 Input data
4.1.1 Typical cases
4.1.1.1 Single-point (fixed-ion) SCF calculation
4.1.1.2 Band structure calculation
4.1.1.3 Structural optimization
4.1.1.4 Molecular Dynamics
4.1.1.5 Polarization via Berry Phase
4.1.1.6 Nudged Elastic Band calculation
4.1.2 Data files
4.2 Phonon calculations
4.2.0.1 Single-q calculation
4.2.0.2 Calculation of interatomic force constants in real space
4.2.0.3 Calculation of electron-phonon interaction coefficients
4.3 Post-processing
4.3.0.1 Plotting selected quantities
4.3.0.2 Band structure, Fermi surface
4.3.0.3 Projection over atomic states, DOS
4.4 Tools
5 Using CP
5.1 Reaching the electronic ground state
5.1.0.1 Important
5.2 Relax the system
5.3 CP dynamics
5.3.0.1 Varying the temperature
5.3.0.2 Nose thermostat for electrons
5.3.0.3 Self-interaction Correction
5.4 Variable-cell MD
5.5 Conjugate Gradient
5.5.0.1 ensemble-DFT
5.6 About nr1b, nr2b, nr3b
6 Performance issues (PWscf)
6.1 CPU time requirements
6.2 Memory requirements
6.3 File space requirements
6.4 Parallelization issues
7 Troubleshooting
7.1 pw.x says 'error while loading shared libraries' or 'cannot open shared object file' and does not start
7.2 errors in examples with parallel execution
7.3 pw.x prints the first few lines and then nothing happens (parallel execution)
7.4 pw.x stops with error while reading data
7.5 pw.x mumbles something like 'cannot recover' or 'error reading recover file'
7.6 pw.x stops with 'inconsistent DFT' error
7.7 pw.x stops with error in cdiaghg or rdiaghg
7.8 pw.x crashes with no error message at all
7.9 pw.x crashes with 'segmentation fault' or similarly obscure messages
7.10 pw.x crashes with 'error in davcio'
7.11 pw.x works for simple systems, but not for large systems or whenever more RAM is needed
7.12 pw.x crashes in parallel execution with an obscure message related to MPI errors
7.13 pw.x runs but nothing happens
7.14 pw.x yields weird results
7.15 pw.x stops with error message "the system is metallic, specify occupations"
7.16 pw.x stops with "internal error: cannot braket Ef " in efermig
7.17 pw.x yields 'internal error: cannot braket Ef' message in efermit, then stops because 'charge is incorrect'
7.18 pw.x yields 'internal error: cannot braket Ef' message in efermit but does not stop
7.19 the FFT grids in pw.x are machine-dependent
7.20 pw.x does not find all the symmetries you expected
7.21 warning: 'symmetry operation # N not allowed'
7.22 I do not get the same results in different machines!
7.23 the CPU time is time-dependent!
7.24 'warning : N eigenvectors not converged ...'
7.25 'warning : negative or imaginary charge...', or '...core charge ...', or 'npt with rhoup< 0
...' or 'rho dw< 0
...'
7.26 self-consistency is slow or does not converge
7.27 structural optimization is slow or does not converge
7.28 pw.x stops during variable-cell optimization in checkallsym with 'non orthogonal operation' error
7.29 some codes in PP/ complain that they do not find some files
7.30 ph.x stops with 'error reading file'
7.31 ph.x mumbles something like 'cannot recover' or 'error reading recover file'
7.32 ph.x says 'occupation numbers probably wrong' and continues; or 'phonon + tetrahedra not implemented' and stops
7.33 ph.x does not yield acoustic modes with
= 0
at
q
= 0
7.34 ph.x yields really lousy phonons, with bad or negative frequencies or wrong symmetries or gross ASR violations
7.35 'Wrong degeneracy' error in star_q
8 Frequently Asked Questions (FAQ)
8.1 Installation
8.1.0.1 ''What Fortran compiler do I need to compile Q-E?''
8.1.0.2 ''Why is
configure
saying that I have no fortran compiler?''
8.1.0.3 ''Why is
configure
saying that my fortran compiler doesn't work?''
8.1.0.4 ''
configure
says 'unsupported architecture', what should I do?''
8.1.0.5 ''Why doesn't
configure
recognize that I have a parallel machine?''
8.1.0.6 ''Compilation fails with "internal error", what should I do?''
8.1.0.7 ''Compilation fails at linking stage: "symbol ... not found"''
8.2 Pseudopotentials
8.2.0.1 ''Can I mix Ultrasoft/Norm-Conserving/PAW pseudopotentials?''
8.2.0.2 ''Where can I find pseudopotentials for atom X?''
8.3 Input data
8.3.0.1 ''Where can I find the crystal structure/atomic positions of XYZ?''
8.3.0.2 ''Where can I find the Brillouin Zone/high-symmetry points/irreps for XYZ?''
8.3.0.3 ''Where can I find Monkhorst-Pack grids of k-points?''
8.3.0.4 ''How do I perform a calculation with spin-orbit interactions?''
8.3.0.5 ''How can I choose parameters for variable-cell molecular dynamics?''
8.4 Parallel execution
8.4.0.1 ''Why is my parallel job running in such a lousy way?''
8.5 Frequent errors during execution
8.5.0.1 ''Why is the code saying "Wrong atomic coordinates"?''
8.5.0.2 ''The code stops with an "error reading namelist xxxx"''
8.5.0.3 ''The code stops with an "error in davcio"''
8.5.0.4 ''The code stops with a "wrong charge" error''
8.6 Self Consistency
8.6.0.1 ''What are the units for quantity XYZ?''
8.6.0.2 ''Self-consistency is slow or does not converge at all''
8.6.0.3 ''How is the charge density (the potential, etc.) stored? What position in real space corresponds to an array value?''
8.6.0.4 ''What is the difference between total and absolute magnetization?''
8.6.0.5 ''How can I calculate magnetic moments for each atom?''
8.6.0.6 ''What is the order of
Y
lm
components in projected DOS / projection of atomic wavefunctions?''
8.6.0.7 ''Why is the sum of partial Lowdin charges not equal to the total charge?''
8.6.0.8 ''Why do I get a strange value of the Fermi energy?''
8.6.0.9 ''Why I don't get zero pressure/stress at equilibrium?''
8.6.0.10 ''Why do I get "negative starting charge"?''
8.6.0.11 ''How do I calculate the work function?''
8.7 Phonons
8.7.0.1 Is there a simple way to determine the symmetry of a given phonon mode?
8.7.0.2 I am not getting zero acoustic mode frequencies, why?
8.7.0.3 Why do I get negative phonon frequencies?
About this document ...
Paolo Giannozzi 2009-10-01