How to parallel SSCHA+QE on two different computing nodes on a cluster?

[hellolori]

Dear Development Team,

I am currently working with a cluster comprised of multiple computing nodes. I have successfully configured SSCHA to run in conjunction with pw.x on a single computing node. For this, I've been using PBS for job scheduling and submission from the login node.

However, when I attempt to run SSCHA+QE across two different computing nodes, I run into issues. Here's a detailed breakdown:

I created an input file, nvt_para.py, for SSCHA, modifying it from the tutorial file nvt_local.py. I adjusted the 'command' value as follows:

command = '~/software/openmpi/4.0.5/bin/mpiexec -n 8 ~/software/QE/6.6_openmpi/bin/pw.x -npool 2 -i PREFIX.pwi > PREFIX.pwo'

The whole content of the file nvt_para.py is shown below:

import sscha, sscha.Ensemble, sscha.SchaMinimizer, sscha.Relax, sscha.Utilities
import cellconstructor as CC, cellconstructor.Phonons
import cellconstructor.Structure, cellconstructor.calculators
import cellconstructor.calculators
from ase.calculators.espresso import Espresso
import numpy as np, matplotlib.pyplot as plt
import sys, os
#
# Initialize the DFT (Quantum Espresso) calculator for H3S
# The input data is a dictionary that encodes the pw.x input file namelist
input_data = {
    'control' : {
        # Avoid writing wavefunctions on the disk
        'disk_io' : 'None',
        # Where to find the pseudopotential
        'pseudo_dir' : '.',
        'outdir' : './outdir',
        'wfcdir' : './wfcdir',
        'tprnfor'  : True,
        'tstress' : True
    },
    'system' : {
        # Specify the basis set cutoffs
        'ecutwfc' : 35,   # Cutoff for wavefunction
        'ecutrho' : 350, # Cutoff for the density
        # Information about smearing (it is a metal)
        'input_dft' : 'blyp', # exchange-correlation functional
        'occupations' : 'smearing',
        'smearing' : 'mv',
        'degauss' : 0.02
    },
    'electrons' : {
        'conv_thr' : 1e-8
    }
}
#
# the pseudopotential for each chemical element
pseudopotentials = {'H' : 'H.pbe-rrkjus_psl.1.0.0.UPF', 'S' : 's_pbe_v1.4.uspp.F.UPF'}
# the kpoints mesh and the offset
kpts = (8,8,8)
koffset = (1,1,1)
#
# Specify the command to call quantum espresso
command = '~/software/openmpi/4.0.5/bin/mpiexec -n 8 ~/software/QE/6.6_openmpi/bin/pw.x  -npool 2 -i PREFIX.pwi > PREFIX.pwo'
#
# Prepare the quantum espresso calculator
calculator = CC.calculators.Espresso(input_data,
                                     pseudopotentials,
                                     command = command,
                                     kpts = kpts,
                                     koffset = koffset)
#calculator = Espresso(pseudopotentials = pseudopotentials, input_data = input_data,
#                        command = command, kpts = kpts, koffset = koffset)
TEMPERATURE = 300
N_CONFIGS = 50
MAX_ITERATIONS = 20
START_DYN = 'start_sscha'
NQIRR = 3
# Let us load the starting dynamical matrix
dyn = CC.Phonons.Phonons(START_DYN, NQIRR)
dyn.Symmetrize()
#
# Initialize the random ionic ensemble
ensemble = sscha.Ensemble.Ensemble(dyn, TEMPERATURE)
#
# Initialize the free energy minimizer
minim = sscha.SchaMinimizer.SSCHA_Minimizer(ensemble)
minim.set_minimization_step(0.01)
#
# Initialize the NVT simulation
relax = sscha.Relax.SSCHA(minim, calculator, N_configs = N_CONFIGS,
                          max_pop = MAX_ITERATIONS)
#
# Define the I/O operations
# To save info about the free energy minimization after each step
ioinfo = sscha.Utilities.IOInfo()
ioinfo.SetupSaving("minim_info")
relax.setup_custom_functions(custom_function_post = ioinfo.CFP_SaveAll)
#
# Run the NVT simulation (save the stress to compute the pressure)
relax.relax(get_stress = True)
#
# If instead you want to run a NPT simulation, use
# The target pressure is given in GPa.
#relax.vc_relax(target_press = 0)
#
# You can also run a mixed simulation (NVT) but with variable lattice parameters
#relax.vc_relax(fix_volume = True)
#
# Now we can save the final dynamical matrix
# And print in stdout the info about the minimization
relax.minim.finalize()
relax.minim.dyn.save_qe("sscha_T{}_dyn".format(TEMPERATURE))

[mesonepigreco]

Since this is a duplicate of the other discussion (probably by mistake), I delete it.
See the response on the other topic.