mirror of https://github.com/abinit/abinit.git
35 lines
1.3 KiB
Plaintext
35 lines
1.3 KiB
Plaintext
Born effective charge and dielectric constant calculation in finite electric field:
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References :
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<li>Responses in the presence of an applied electric field
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<br><cite> XJ Wang and D. Vanderbilt, Phys. Rev. B 75, 115116 (2007).</cite>
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<br><cite> XJ Wang and D. Vanderbilt, Phys. Rev. B 74, 054304 (2006).</cite>
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The calculations require three steps:
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1. run a scf ground-state calculation at zero electric field
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to get wave functions for the ground-state calculation in finite electric
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fields.
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2. run a scf ground-state calculation in finite electric field. The
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electric field is controlled by the input variable 'efield'. And
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'berryopt' should be 4. The input variable 'kptopt' should be set
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to be 2.
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3. Based on the ground-state wave functions obtained in step (2), linear response
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calculations of phonon perturbation and electric field perturbation are performed.
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The critical input variables are:
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rfphon30 1
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rfatpol30 1 2
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rfdir30 1 1 1
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rfelfd30 3 #turn on electric field perturbation in finite electric field.
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nqpt30 1
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kptopt30 3
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berryopt30 4
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nsym30 1 #use no symmetry
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qpt30 0.0 0.0 0.0
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The choice of k-point sampling N x N x N should be the same in the three steps
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and N is restricted to the even integers (2,4,6,8...).
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