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Constraint DFT for non-collinear spin orientation-problem in fixing spin orientation
Date: 2020/04/27 16:09
Name: Maedeh   <rasekh.maede@gmail.com>

Dear OpenMX developers,
Hi,

I want to calculate the energy of AFM and FM magnetic phases for the below structure while it is including SOC.
but for AFM the spins rotate to the FM phase during the calculation and it has convergence problems.

I also have a couple of questions about Constraint DFT for non-collinear spin orientation:

How can I choose this setting and how far can I increase it?
scf.Constraint.NC.Spin.v 0.5 # default=0.0(eV)

while it has its default, the constraint won't be applied on the atoms [however, it is on (The '1' in the 12th column)]?




Here is my .dat file:

# Definition of Atomic Species#

Species.Number 2
<Definition.of.Atomic.Species
Cr Cr6.0-s2p2d1 Cr_PBE13
I I7.0-s2p2d1 I_PBE13
Definition.of.Atomic.Species>

# Atoms #
Atoms.Number 32
Atoms.SpeciesAndCoordinates.Unit FRAC # Ang|AU
<Atoms.SpeciesAndCoordinates
1 I 0.00030532130725 0.32423921655213 0.58300663022536 4 3 0.0 0.0 0.0 0.0 0 off
2 I 0.00529022923998 0.83148495792941 0.58151108946555 4 3 0.0 0.0 0.0 0.0 0 off
3 I 0.49217414979559 0.33236003939656 0.58254516650058 4 3 0.0 0.0 0.0 0.0 0 off
4 I 0.50386951837414 0.82556870869281 0.58301107665734 4 3 0.0 0.0 0.0 0.0 0 off
5 I 0.50042020362509 0.17756259714911 0.41995647783044 4 3 0.0 0.0 0.0 0.0 0 off
6 I 0.49570607600098 0.67021435747622 0.41533028791183 4 3 0.0 0.0 0.0 0.0 0 off
7 I 0.99557809952052 0.17363444359182 0.41298155339895 4 3 0.0 0.0 0.0 0.0 0 off
8 I 0.99914651392837 0.67579261836355 0.41310227540164 4 3 0.0 0.0 0.0 0.0 0 off
9 I 0.17412004057936 0.17710142325043 0.58154535450568 4 3 0.0 0.0 0.0 0.0 0 off
10 I 0.18028219749831 0.68175500423269 0.58327354678432 4 3 0.0 0.0 0.0 0.0 0 off
11 I 0.67354404617072 0.16301940172793 0.58270424972519 4 3 0.0 0.0 0.0 0.0 0 off
12 I 0.68143273440478 0.67936052887507 0.58318447973162 4 3 0.0 0.0 0.0 0.0 0 off
13 I 0.31733729681366 0.31988347644568 0.41277189455435 4 3 0.0 0.0 0.0 0.0 0 off
14 I 0.32316413613908 0.82226399092335 0.41518883503351 4 3 0.0 0.0 0.0 0.0 0 off
15 I 0.81599669835145 0.31958269938758 0.41972292277140 4 3 0.0 0.0 0.0 0.0 0 off
16 I 0.81939198247289 0.81828788118390 0.41288111495781 4 3 0.0 0.0 0.0 0.0 0 off
17 I 0.32649375761266 0.00526866167192 0.58324039974949 4 3 0.0 0.0 0.0 0.0 0 off
18 I 0.32406235464354 0.50157136668383 0.58320808202135 4 3 0.0 0.0 0.0 0.0 0 off
19 I 0.82891168819798 0.00004685876858 0.58144192708413 4 3 0.0 0.0 0.0 0.0 0 off
20 I 0.84257426699665 0.51313972642672 0.58272278071622 4 3 0.0 0.0 0.0 0.0 0 off
21 I 0.17095917619419 0.49791408537332 0.41514198067381 4 3 0.0 0.0 0.0 0.0 0 off
22 I 0.17452494702925 0.99785891537337 0.41294946622572 4 3 0.0 0.0 0.0 0.0 0 off
23 I 0.67404069818669 0.49341236753548 0.41993674137584 4 3 0.0 0.0 0.0 0.0 0 off
24 I 0.67334719634013 0.99439055825590 0.41269599484449 4 3 0.0 0.0 0.0 0.0 0 off
25 Cr 0.16434831623308 0.33296608364853 0.49797076736749 10 4 0.0 0.0 0.0 0.0 1 off
26 Cr 0.16804296968022 0.83534910243498 0.49812160862832 10 4 0.0 0.0 0.0 0.0 1 off
27 Cr 0.66679299430407 0.33358376279523 0.51121934202180 10 4 0.0 0.0 0.0 0.0 1 off
28 Cr 0.66673646724400 0.83176552603184 0.49801156729792 10 4 0.0 0.0 0.0 0.0 1 off
29 Cr 0.33061369030321 0.16714588466602 0.49812779489290 4 10 180.0 0.0 0.0 0.0 1 off
30 Cr 0.33278465778779 0.66620627820279 0.49910833907794 4 10 180.0 0.0 0.0 0.0 1 off
31 Cr 0.83218101188327 0.16323031170790 0.49809581981053 4 10 180.0 0.0 0.0 0.0 1 off
32 Cr 0.83602918029811 0.66861569396160 0.49822134335169 4 10 180.0 0.0 0.0 0.0 1 off
Atoms.SpeciesAndCoordinates>

Atoms.UnitVectors.Unit Ang # Ang|AU
<Atoms.UnitVectors
13.7301998138 0.0000000000 0.0000000000
-6.8482827023 11.9003954118 0.0000000000
-0.2582355712 -0.4465478669 18.9625857745
Atoms.UnitVectors>


#
# SCF or Electronic System
#

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

scf.SpinPolarization NC # On|Off|NC
scf.SpinOrbit.Coupling on # On|Off, default=off
scf.Constraint.NC.Spin on2 # on|on2|off, default=off
scf.Constraint.NC.Spin.v 0.5 # default=0.0(eV)

scf.ElectronicTemperature 300.0 # default=300 (K)
scf.energycutoff 220 # default=150 (Ry)
scf.maxIter 1000 # default=40
scf.EigenvalueSolver band # Recursion|Cluster|Band
scf.Kgrid 7 7 1 # means 4x4x4
scf.Mixing.Type rmm-diis # Simple|Rmm-Diis|Gr-Pulay
scf.Init.Mixing.Weight 0.030 # default=0.30
scf.Min.Mixing.Weight 0.001 # default=0.001
scf.Max.Mixing.Weight 0.400 # default=0.40
scf.Kerker.factor 1.0 # default=1.0
scf.Mixing.History 14 # default=5
scf.Mixing.StartPulay 6 # default=6
scf.Mixing.EveryPulay 1 # default=5
scf.criterion 1.0e-6 # default=1.0e-6 (Hartree)






Best regards,
Maedeh
メンテ
Page: [1]

Re: Constraint DFT for non-collinear spin orientation-problem in fixing spin orientation ( No.1 )
Date: 2020/04/27 18:53
Name: Naoya Yamaguchi

Dear Maedeh,

For atoms 29-32, the spin configuration of "4 10 180.0 0.0" is equivalent to "10 4 0.0 0.0".
I guess that the initial one corresponds the FM phase.
Can you try "10 4 180.0 0.0" or "4 10 0.0 0.0"?

Regards,
Naoya Yamaguchi
メンテ
Re: Constraint DFT for non-collinear spin orientation-problem in fixing spin orientation ( No.2 )
Date: 2020/04/27 20:06
Name: Maedeh  <rasekh.maede@gmail.com>

Dear Naoya

I tried this:

10 4 0.0 0.0
10 4 0.0 0.0
10 4 0.0 0.0
10 4 0.0 0.0
4 10 0.0 0.0
4 10 0.0 0.0
4 10 0.0 0.0
4 10 0.0 0.0

and here are the results:

Total spin moment (muB) 0.014972127 Angles (Deg) 0.321415914 104.153389740
Up Down Sum Diff theta phi
....

25 Cr 9.42364 4.69444 14.11808 4.72920 0.00155 125.17505
26 Cr 9.42364 4.69448 14.11812 4.72916 0.00118 17.13873
27 Cr 9.40294 4.66332 14.06626 4.73962 0.00026 -29.80765
28 Cr 9.42358 4.69440 14.11797 4.72918 0.00253 262.48183
29 Cr 9.42670 4.69989 14.12660 4.72681 179.99889 74.52397
30 Cr 9.42360 4.69403 14.11763 4.72957 179.99982 42.69018
31 Cr 9.42703 4.70011 14.12713 4.72692 179.99896 178.95197
32 Cr 9.42702 4.70007 14.12708 4.72695 179.99889 -41.73739

converged with 78 scf.

Thank you so much...

Best regards,
Maedeh
メンテ

Page: [1]

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