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Andersen Force Therom and MCA

Elk Users
2018-04-10
2020-05-07
  • Robert D. Nielsen

    Hello,

    I am working with an MCA calculation and am trying to go about it using the Andersen force therom but am having a bit of confusion.

    When i set tasks to 1 and set the maxscl to 1, I get the same results back as if they were not modified. So I then set the maxscl to 2 and saw that the moment was changing from the original the described moment by the mommtfix tag, but not entirely equal to it. It seems that the magnetic moments aren't being totally constrained into the direction of mommtfix.

    My question is how do I guarentee that the moments will be entirely fixed

    Below is my elk.in:

    tasks
    1

    fsmtype
    -2

    mommtfix
    1 1 -.99999999999999999999 0 -.00000000000010338076
    1 2 -.99999999999999999999 0 -.00000000000010338076
    1 3 -.99999999999999999999 0 -.00000000000010338076
    1 4 -.99999999999999999999 0 -.00000000000010338076
    1 5 -.99999999999999999999 0 -.00000000000010338076
    1 6 -.99999999999999999999 0 -.00000000000010338076
    1 7 -.99999999999999999999 0 -.00000000000010338076
    1 8 -.99999999999999999999 0 -.00000000000010338076
    1 9 -.99999999999999999999 0 -.00000000000010338076

    maxscl
    2

    beta0
    0.00

    autolinengy
    .true.

    autoswidth
    .true.

    spinpol
    .true.

    spinorb
    .true.

    bfieldc
    .00000099999999999999 0 .00000000000000000010

    reducebf
    0.99

    taufsm
    0.00

    lorbcnd
    .true.

    mixtype
    0

    xctype
    3

    lda+u
    1 1
    1 2 0.12 0.00
    1 3 0.27 0.041

    ngridk
    8 8 8

    sppath
    '/home/rnielse5/ELK/elk-4.3.6/species/'

    scale
    1.0

    avec
    0.000000000 14.58084227 14.58084227
    14.58084227 0.000000000 14.58084227
    4.860280756 4.860280756 0.000000000

    atoms
    2 : nspecies
    'Eu.in' : spfname
    9 : natoms; atpos, bfcmt below
    0.85394315 0.82685351 0.47840114 0.00000000 0.00000000 0.00000000
    0.82863211 0.17204837 0.49888766 0.00000000 0.00000000 0.00000000
    0.82614444 0.50481685 0.50337630 0.00000000 0.00000000 0.00000000
    0.16288650 0.83575154 0.50190124 0.00000000 0.00000000 0.00000000
    0.17003654 0.15833943 0.50769192 0.00000000 0.00000000 0.00000000
    0.16751530 0.50795342 0.48646442 0.00000000 0.00000000 0.00000000
    0.47392726 0.84533883 0.52137614 0.00000000 0.00000000 0.00000000
    0.48356794 0.18580605 0.49615846 0.00000000 0.00000000 0.00000000
    0.49216734 0.49992602 0.51190833 0.00000000 0.00000000 0.00000000
    'O.in' : spfname
    6 : natoms; atpos, bfcmt below
    -0.00009554 0.00017149 -0.00006532 0.00000000 0.00000000 0.00000000
    0.00194626 0.66891734 0.99358763 0.00000000 0.00000000 0.00000000
    0.32419812 0.00684780 0.00382806 0.00000000 0.00000000 0.00000000
    0.33057764 0.33752519 0.99799793 0.00000000 0.00000000 0.00000000
    0.32692486 0.67088759 0.00333010 0.00000000 0.00000000 0.00000000
    0.65925164 0.34014504 0.00100350 0.00000000 0.00000000 0.00000000

    Thank you,

    Robert D. Nielsen

     

    Last edit: Robert D. Nielsen 2018-04-10
  • Andrew Shyichuk

    Andrew Shyichuk - 2020-05-07

    Dear Robert,

    Momfix works via self-consistent changes in the cell magnetic field (or atomic fileds) in order to approach the target moment.
    It is thus not exactly fixed.

    You do not need to use reducebf and bfieldc with momfix.

    Best regards.
    Andrew

     

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