mirror of https://gitlab.com/QEF/q-e.git
16 lines
880 B
Plaintext
16 lines
880 B
Plaintext
This example illustrates how to use the phonon code to calculate
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the dispersions along some the a path of the BZ for two-dimensional materials.
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The Gamma-K-M-Gamma path of monolayer Boron Nitride is used as an example.
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The calculation proceeds as follows
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1) make a self-consistent calculation for BN, setting assume_isolated='2D'
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in the SYSTEM namelist to activate the 2D Coulomb cutoff.
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(input=bn.scf.in, output=bn.scf.out)
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2) make the phonon calculation for a grid of 881 q-points. The 2D Coulomb
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cutoff is automatically activated for a phonon run done on top of a 2D scf run
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(no need to specify any additional flag in the phonon input).
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3) interpolate the phonon dispersion using q2r and matdyn. This time, and especially for polar 2D material, one should set :
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loto_2d=.true.
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in input so that LO-TO splitting is treated in the correct two-dimensional framework. |