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converged structures
Date: 2020/07/24 01:38
Name: Elie Moujaes

Dear all

I am a new user to OpenMX. I have two questions :

1) I am have relaxed an NiO structure using the RF scheme. It went fine and the relaxed atomic positions are (in angstroms):

Ni 0.74149 0.77020 0.22817 -0.000181518815361 -0.000226570321314 0.000247195636509
Ni 2.21949 2.26073 0.28733 -0.000244385568172 0.000116824667496 -0.000221006662608
O 2.45844 0.39774 -0.19814 -0.000043777735287 -0.000082285656731 0.000044088311607
O 1.69656 1.73548 3.40148 0.000005078942934 0.000025189669646 -0.000055359732242

However when i ran an scf calculation with the new atomic positions, the forces were high, namely:

1 Ni 0.74149 0.77020 0.22817 -0.758012495027 -0.757585795749 -0.760117130739
2 Ni 2.21949 2.26073 0.28733 -0.502903869327 -0.502179606284 -0.504912917322
3 O 2.45844 0.39774 -0.19814 -0.016542572868 -0.016407886021 -0.014922802074
4 O 1.69656 1.73548 3.40148 -0.003859345506 -0.003836669998 -0.000980540614

What could have gone wrong?

Regards
メンテ
Page: [1]

Re: converged structures ( No.1 )
Date: 2020/07/24 10:36
Name: T. Ozaki

Hi,

Could you show us your input files for the first and second calculations?

Regards,

TO
メンテ
Re: converged structures ( No.2 )
Date: 2020/07/25 02:04
Name: Elie Moujaes

Dear Professor Ozaki,

Thanks for your reply:

The input for MD calculations is :

System.Name NiO-bulk-rel
level.of.stdout 1 # default=1 (1-3)
level.of.fileout 1 # default=1 (1-3)
DATA.PATH /home/eamoujaes/openmx3.9/DFT_DATA19


#
# Definition of Atomic Species
#

Species.Number 2
<Definition.of.Atomic.Species
Ni Ni6.0S-s2p2d2f1 Ni_CA19S
O O5.0-s2p2d1 O_CA19
Definition.of.Atomic.Species>

#Atoms
#
Atoms.Number 4
Atoms.SpeciesAndCoordinates.Unit AU # Ang|AU
<Atoms.SpeciesAndCoordinates
1 Ni 0.0 0.0 0.0 10.0 6.0 on
2 Ni 3.94955 3.94955 0.0 6.0 10.0 on
3 O 3.94955 0.0 0.0 3.0 3.0 on
4 O 3.94955 3.94955 3.94955 3.0 3.0 on
Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit AU # Ang|AU
<Atoms.UnitVectors
7.89910 3.94955 3.94955
3.94955 7.89910 3.94955
3.94955 3.94955 7.89910
Atoms.UnitVectors>
#
# SCF or Electronic System
#

scf.XcType LSDA-CA # LDA|LSDA-CA|GGA-PBE

# DFT+U part #
scf.Hubbard.U Off # On|Off, default=off
#scf.Hubbard.Occupation dual # onsite|full|dual, default=dual
#scf.DFTU.Type 2 # 1:Simplified(Dudarev)|2:General, default=1
#scf.dc.Type cFLL # sFLL|sAMF|cFLL|cAMF, default=sFLL
scf.Slater.Ratio 0.625 # default=0.625
scf.Yukawa off # default=off
##############

scf.SpinPolarization On # On|Off
scf.ElectronicTemperature 500.0 # default=300 (K)
scf.energycutoff 130.0 # default=150 (Ry)
scf.maxIter 800 # default=40
scf.EigenvalueSolver band # Recursion|Cluster|Band
scf.Kgrid 5 5 5 # means 4x4x4
scf.Mixing.Type Rmm-Diis # Simple|Rmm-Diis|Gr-Pulay
.
.
.
.
For the scf of the relaxed structure (i took the coordinates from the xyz produced with forces being almos 0):

File Name
#

System.CurrrentDirectory /fefs1/physics/eamoujaes/NiO/AFMII/bulk/ # default=./
System.Name NiO-bulk-scf
level.of.stdout 1 # default=1 (1-3)
level.of.fileout 1 # default=1 (1-3)
DATA.PATH /home/eamoujaes/openmx3.9/DFT_DATA19


#
# Definition of Atomic Species
#

Species.Number 2
<Definition.of.Atomic.Species
Ni Ni6.0S-s2p2d2f1 Ni_CA19S
O O5.0-s2p2d1 O_CA19
Definition.of.Atomic.Species>

#Atoms
#
Atoms.Number 4

Atoms.SpeciesAndCoordinates.Unit Ang # Ang|AU

<Atoms.SpeciesAndCoordinates
1 Ni 0.74149 0.77020 0.22817 10 6 0n
2 Ni 2.21949 2.26073 0.28733 6 10 on
3 O 2.45844 0.39774 -0.19814 3.0 3.0 on
4 O 1.69656 1.73548 3.40148 3.0 3.0 on
Atoms.SpeciesAndCoordinates>
Atoms.UnitVectors.Unit AU # Ang|AU
<Atoms.UnitVectors
7.89910 3.94955 3.94955
3.94955 7.89910 3.94955
3.94955 3.94955 7.89910
Atoms.UnitVectors>
#
# SCF or Electronic System
#

scf.XcType LSDA-CA # LDA|LSDA-CA|GGA-PBE

# DFT+U part #
scf.Hubbard.U Off # On|Off, default=off
#scf.Hubbard.Occupation dual # onsite|full|dual, default=dual
#scf.DFTU.Type 2 # 1:Simplified(Dudarev)|2:General, default=1
#scf.dc.Type cFLL # sFLL|sAMF|cFLL|cAMF, default=sFLL
scf.Slater.Ratio 0.625 # default=0.625
scf.Yukawa off # default=off
##############

scf.SpinPolarization On # On|Off
scf.ElectronicTemperature 500.0 # default=300 (K)
scf.energycutoff 130.0 # default=150 (Ry)
scf.maxIter 800 # default=40
.
.
.


Regards

メンテ

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