[QE-users] Change in temperature control for md simulation in QE 6.4.1 compared with 6.3 -- perhaps instead an issue with detecting symmetry??

Lorenzo Paulatto paulatz at gmail.com
Thu Apr 18 11:11:25 CEST 2019


> symmetry detection?    We did put nosym=.true. but the code seems to 
> have set invsym=.true. anyway. 

I see what you mean,
with the exact same input version 6.3 set the variable invsym, from 
symm_base to false, while the current version sets it to true.

This breaks start_therm because the only possible initial velocities 
that respect the constraint in this case are all zero.

The bug is that version 6.3 sets invsym AFTER enforcing nosym=.true., 
while git version sets invsym BEFORE enforcing nosym=.true., the 
subroutine find_sym is identical

The change seems to have occurred in commit 23fb73f9b7 inside 
PW/src/setup.f90 I'll let Paolo Giannozzi have a look before going 
deeper, as I do not immediately understand what has changed, I think it 
has something to do with nrot_ vs. nrot, as the former is 1 but the 
latter is 48 before the call to find_sym in setup.f90 line 513, but 
find_sym internally uses nrot.

cheers


Perhaps it is intended that users should
> move atoms off of their symmetry positions before running MD 
> simulations?       Thanks for your advice about this.    Natalie
> 
> N. A. W. Holzwarth                                       email: 
> natalie at wfu.edu <mailto:natalie at wfu.edu>
> Department of Physics                                  web: 
> http://www.wfu.edu/~natalie
> Wake Forest University                                 phone: 
> 1-336-758-5510
> Winston-Salem, NC 27109 USA                     office: Rm. 300 Olin 
> Physical Lab
> 
> 
> On Wed, Apr 10, 2019 at 6:29 PM Holzwarth, Natalie <natalie at wfu.edu 
> <mailto:natalie at wfu.edu>> wrote:
> 
>     Dear Quantum Espresso developers,
>             Hopefully this might be something that is easy to track down
>     but I cannot figure it out.   We noticed that we cannot set the
>     initial temperature in our md simulations in QE 6.4.1  (or 6.4) in
>     the same way that works fine in QE 6.3.   For example, in a simple
>     test , the comparison between the results for " grep temperature 
>     *out"   is:
>                        QE   6.3                                QE 6.4.1
>           temperature    =  1800.00000000 K       temperature    =   
>       0.00000000 K
>           temperature    =  1798.79298998 K       temperature    =   
>       0.00000000 K
>           temperature    =  1795.18924725 K       temperature    =   
>       0.00000001 K
>           temperature    =  1789.20477087 K       temperature    =   
>       0.00000002 K
>           temperature    =  1780.85173941 K       temperature    =   
>       0.00000048 K
>           temperature    =  1770.15802096 K       temperature    =   
>       0.00000014 K
>           temperature    =  1757.15885289 K       temperature    =   
>       0.00000032 K
>           temperature    =  1741.89911601 K       temperature    =   
>       0.00000575 K
>           temperature    =  1724.42918183 K       temperature    =   
>       0.00001204 K
>           temperature    =  1704.80836203 K       temperature    =   
>       0.00001108 K
>           temperature    =  1683.10589232 K       temperature    =   
>       0.00000872 K
>     The sample input file is pasted below.   The only difference between
>     the runs is the version of QE.
>        Thanks in advance for your suggestions.    Sincerely, Natalie
>     -------------------sample input file for md
>     run-----------------------------
>     #!/bin/tcsh
>     #
>     #SBATCH --nodes=1
>     #SBATCH --ntasks-per-node=8
>     #SBATCH --cpus-per-task=1
>     #SBATCH --account="natalieGrp"
>     #SBATCH --output="JOB-%j.o"
>     #SBATCH --error="JOB-%j.e"
>     #SBATCH --mail-user=natalie at wfu.edu <mailto:natalie at wfu.edu>
>     #SBATCH --mail-type=BEGIN,END,FAIL
>     #SBATCH --job-name="NaCl"
>     #SBATCH --time=0-10:00:00
>     #SBATCH --mem=24gb
>     #SBATCH --partition=small
>     umask 002
>     # Note: SLURM has no batch input for cputime, excluding.
>     #
>     source /etc/profile.d/modules.csh
>     module purge
>     module load rhel7/openmpi/3.1.1-intel-2018
>     #
>     echo 'hostname' `/bin/hostname`
>     echo 'job directory' `pwd`
>     #
>     setenv TMPDIR /scratch/$SLURM_JOBID
>     echo 'Reset TMPDIR for this job to ' $TMPDIR
> 
>     set PW=/home/natalie/EL7/publiccode/QE/qe-6.4.1/bin/pw.x
> 
>     #NOTE:SLURM defaults to running jobs in the directory where submitted;
>     #NOTE:Consider --workdir directive instead; and check functionality!
>     cd ${SLURM_SUBMIT_DIR}
> 
>     cat > NaCl.in << EOF
> 
>     &CONTROL
>        calculation = "md",
>        pseudo_dir  =
>     '/deac/natalieGrp/wfurc9/natalie/EL6/rc9/PAWatoms/poscorenhat/',
>        verbosity   = "high",
>        outdir      = "$TMPDIR/",
>        prefix      = "conv",
>        restart_mode = 'from_scratch',
>        nstep = 30,
>        dt = 20,
>        forc_conv_thr = 1.0D-5,
>        etot_conv_thr = 1.0D-6,
>        tstress = .true.,
>        tprnfor = .true.,
>     /
>     &SYSTEM
>        ibrav       = 1,
>        celldm(1)=1.0331018E+01,
>        nat         = 8,
>        ntyp        = 2,
>        nosym       =.TRUE.,
>        ecutwfc     = 64.D0,
>        use_all_frac = .TRUE.,
>        occupations = "smearing",
>        smearing    = "gaussian",
>        degauss     = 0.001D0,
>     /
>     &ELECTRONS
>        conv_thr    = 1.D-8,
>        electron_maxstep = 200,
>     /
>     &IONS
>       ion_dynamics = 'verlet',
>       ion_temperature = 'initial',
>       tempw = 1800.d0,
>       pot_extrapolation = 'second-order',
>       wfc_extrapolation = 'second-order',
>     /
>     &CELL
>        cell_dynamics='none',
>        wmass = 1.0,
>        press = 0.0,
>     /
>     ATOMIC_SPECIES
>     Na  22.989769  Na.LDA-PW-paw.UPF
>     Cl  35.45   Cl.LDA-PW-paw.UPF
>     ATOMIC_POSITIONS {crystal}
>     Na       0.000000000  0.000000000  0.000000000
>     Na       0.500000000  0.500000000  0.000000000
>     Na       0.000000000  0.500000000  0.500000000
>     Na       0.500000000  0.000000000  0.500000000
>     Cl       0.500000000  0.500000000  0.500000000
>     Cl       0.000000000  0.000000000  0.500000000
>     Cl       0.500000000  0.000000000  0.000000000
>     Cl       0.000000000  0.500000000  0.000000000
>     K_POINTS AUTOMATIC
>     2 2 2 1 1 1
>     EOF
> 
>     mpirun $PW  -in  NaCl.in  >  NaCl.out
> 
>     -------------------------------------------------------------------------------------
> 
>     N. A. W. Holzwarth                                       email:
>     natalie@ <mailto:natalie at wfu.edu>
>     Department of Physics                                  web:
>     http://www.wfu.edu/~natalie
>     Wake Forest University                                 phone:
>     1-336-758-5510
>     Winston-Salem, NC 27109 USA                     office: Rm. 300 Olin
>     Physical Lab
> 
> 
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> 

-- 
Lorenzo Paulatto - Paris


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