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Problem with geometry optimization
Date: 2023/11/21 20:25
Name: Lim

Dear experts,

I have a question regarding the use of geometry optimization.
I'm trying to use geometry optimization for a Cu primitive cell.
After completing the full relaxation, I plan to calculate the band structure based on the results.
I am trying to perform relaxation on both atom and cells using the OptC5 method, but I am encountering a problem.
I am doing the relaxation of a simple Cu primitive cell with a single atom, but the relaxation is not converging well. Despite using a sufficient number of cores and processes, I am experiencing a shortage of memory.
I used the Materials Project to obtain the initial coordinates and initial unit cell data.
What parameters should I change to achieve better convergence of geometry optimization

Below is my input data.

#  The file was generated by the OpenMX Viewer


System.CurrrentDirectory        ./
System.Name                    Cu_primitive
level.of.stdout                  1
level.of.fileout                  1

Species.Number                    1
  Cu    Cu6.0H-s3p2d1    Cu_PBE19H

Atoms.Number                      1
Atoms.SpeciesAndCoordinates.Unit  FRAC
  1    Cu    0.0000000  0.0000000  0.0000000    9.5  9.5

Atoms.UnitVectors.Unit            Ang
    2.5606189    0.0000000    0.0000000
    1.2803095    2.2175610    0.0000000
    1.2803095    0.7391870    2.0907366

scf.XcType                    GGA-PBE
scf.SpinPolarization          off
scf.ElectronicTemperature    300.0
scf.energycutoff              220.0
scf.maxIter                  100
scf.EigenvalueSolver          band
scf.Kgrid                    9  9  9
scf.Mixing.Type              rmm-diisk
scf.Init.Mixing.Weight        0.05
scf.Min.Mixing.Weight        0.01
scf.Max.Mixing.Weight        0.30
scf.Mixing.History            25
scf.Mixing.StartPulay        15
scf.criterion                1.0e-7    # default=1.0e-6 (Hartree)

MD.Type                    OptC5      # Nomd|Opt|DIIS|NVE|NVT_VS|NVT_NH
MD.Opt.DIIS.History          10        # default=7
MD.Opt.StartDIIS            10        # default=5
MD.Opt.EveryDIIS          10000      # default=10
MD.maxIter                  400        # default=1
MD.Opt.criterion          0.00003      # default=1.0e-4 (Hartree/bohr)
1 1 1 1

#MD.Type                      OptC2
#MD.maxIter                    300
#MD.TimeStep                  1.0
#MD.Opt.criterion              0.0003

Dos.fileout                  off
Dos.Erange                    -25.0  20.0
Dos.Kgrid                    8  8  8

Band.dispersion              off
Band.Nkpath                  5
  40  0.000000 0.000000 0.000000  0.500000 0.000000 0.500000  G X
  40  0.500000 0.000000 0.500000  0.500000 0.250000 0.750000  X W
  40  0.500000 0.250000 0.750000  0.500000 0.500000 0.500000  W L
  40  0.500000 0.500000 0.500000  0.000000 0.000000 0.000000  L G
  40  0.000000 0.000000 0.000000  0.375000 0.375000 0.750000  G K
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Re: Problem with geometry optimization ( No.1 )
Date: 2023/11/21 20:41
Name: Masanobu Miyata  <>


The crystal system of pure Cu is a face-centered cubic, indicating that the primitive lattice vector should be constrained under a = b = c. Therefore, you should not use OptC5(without constrain) but OptC3(a = b = c).

Best regards
Re: Problem with geometry optimization ( No.2 )
Date: 2023/11/22 11:17
Name: Lim

Thank you for your response.

I believe that OptC3 involves fixing the symmetry during optimization.
However, I think that if full relaxation like OptC5 also converges, it can yield the same results.
I believe that performing a full relaxation during DFT calculations for optimization is more reliable, which is why I chose to use OptC5.
I have observed that full relaxation for primitive cells of other metals like Ru and Mo converges in less than a minute, but I am curious why the Cu primitive cell takes much longer and does not converge as easily

Could you provide any tips on how to ensure good convergence through full relaxation optimization?
Re: Problem with geometry optimization ( No.3 )
Date: 2023/11/26 01:16
Name: Lim

When I perform OptC5 optimization on the Cu primitive cell, the calculation does not proceed after the phrase 'Invalid access in truncation.c' appears in the .out file. What could be the reason for this?

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