LKPROJ: Difference between revisions

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This unit cell has to be supplied in the file {{FILE|POSCAR.prim}}, in the usual {{FILE|POSCAR}} format.
This unit cell has to be supplied in the file {{FILE|POSCAR.prim}}, in the usual {{FILE|POSCAR}} format.


As a first step, the '''k'''-projection scheme determines the set {'''k′'''}, of '''k'''-points in the irreducible part of the first Brillouin zone of the structure given in {{FILE|POSCAR.prim}}, for which
:<math>
\langle \mathbf{k}'+\mathbf{G}' | \mathbf{k}+\mathbf{G}\rangle \neq 0
</math>
where '''G''' and '''G&prime;''' are reciprocal space vectors in the reciprocal spaces of the structures specified in {{FILE|POSCAR}} and {{FILE|POSCAR.prim}}, respectively. As usual, the set of points {'''k'''} is specified in the {{FILE|KPOINTS}} file.
The set {'''k&prime;'''} is written to the {{FILE|OUTCAR}} file. Look at the part of the {{FILE|OUTCAR}} following <tt>NKPTS_PRIM</tt>.
Once the set {'''k&prime;'''} has been determined VASP will compute the following
:<math>
\Kappa_{n\mathbf{k}\sigma\mathbf{k}'}=\sum_{\mathbf{GG}'}
|\langle \mathbf{k}'+\mathbf{G}'| \mathbf{k}+\mathbf{G}\rangle
\langle \mathbf{k}+\mathbf{G} | \Psi_{n\mathbf{k}\sigma}\rangle |^2
</math>
and writes this information onto the {{FILE|vasprun.xml}} file.
One may, for instance, use this scheme to project the
== Related Tags and Sections ==
{{TAG|KPROJ_THRESHOLD}}


----
----

Revision as of 13:33, 3 December 2012

LKPROJ = .TRUE. | .FALSE.
Default: LKPROJ = .FALSE. 

Description: switches on the k-point projection scheme.


For LKPROJ=.TRUE., VASP will project the orbitals onto the reciprocal space of an alternative unit cell. This unit cell has to be supplied in the file POSCAR.prim, in the usual POSCAR format.

As a first step, the k-projection scheme determines the set {k′}, of k-points in the irreducible part of the first Brillouin zone of the structure given in POSCAR.prim, for which

where G and G′ are reciprocal space vectors in the reciprocal spaces of the structures specified in POSCAR and POSCAR.prim, respectively. As usual, the set of points {k} is specified in the KPOINTS file. The set {k′} is written to the OUTCAR file. Look at the part of the OUTCAR following NKPTS_PRIM.

Once the set {k′} has been determined VASP will compute the following

and writes this information onto the vasprun.xml file.

One may, for instance, use this scheme to project the

Related Tags and Sections

KPROJ_THRESHOLD


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