Comment 1 for bug 1799991

Many thanks for reporting the bug. This has now been fixed in the 4.1 branch and will be available in the coming 4.1-b4 release.

I tested this with this smaller fdf:

Diag.ParallelOverK True

WriteForces True
WriteBands True

SaveRho True
SaveElectrostaticPotential True

LatticeConstant 1.0 Ang
%block LatticeVectors
 3.80000000 0.00000000 0.00000000
 0.00000000 3.80000000 0.00000000
 0.00000000 0.00000000 11.90000000
%endblock LatticeVectors

NumberOfAtoms 4
AtomicCoordinatesFormat Ang
%block AtomicCoordinatesAndAtomicSpecies
 0.00000000 0.00000000 0.00000000 1 # 1: O
 1.90000000 0.00000000 0.00000000 1 # 2: O
 0.00000000 1.90000000 0.00000000 1 # 3: O
 1.90000000 1.90000000 0.00000000 1 # 4: O
%endblock AtomicCoordinatesAndAtomicSpecies

NumberOfSpecies 1
%block ChemicalSpeciesLabel
 1 8 O
%endblock ChemicalSpeciesLabel

#Real space grid
MeshCutoff 100.0 Ry

KgridCutoff 20.0 Ang
ElectronicTemperature 0.03 eV

Grid.CellSampling [1 1 3]

# Convergence of SCF
SCFMustConverge False
MaxSCFIterations 8000

DM.MixingWeight 0.01
DM.UseSaveDM True