[Pw_forum] problem of the convergence in surface calculation of magnetic insulator

[yukihiro_okuno at fujifilm.co.jp]

Dear PWSCF users and developers.

I'm now using PWSCF in order to calculate the electric state of the

magnetic insulator. The material is ferri magnetic compounds and

has  64 atom in the unit cell.

We set LDA+U calculation. The results are not converged.

I have also experience that the convergence is not achieved

in anti-ferromagnetic materials with impurity.

How we should treat such a difficult convergence materials, and

in general what parameters should we corrected ?

A parts of my input is as follow.

 &system
    ibrav=4
    celldm(1)=20.0
    celldm(3)=3.93844842285
    nat=64
    ntyp=4
    nbnd=320
    ecutwfc =50.0
    ecutrho = 500.0
    nspin = 2
    starting_magnetization(1) = 0.0
    starting_magnetization(2) = 3.0
    starting_magnetization(3) = -3.0
    starting_magnetization(4) = 0.0
    degauss=0.01
    lda_plus_u = .TRUE.
    occupations='smearing'
    smearing='gauss'
    degauss=0.05
    Hubbard_U(2) = 5.0
    Hubbard_U(3) = 5.0
 /
 &electrons
    conv_thr = 1e-7,
    mixing_mode = 'plain'
    mixing_beta=0.1,
 /

Sincerely,

Yukihiro Okuno.
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