LORBIT: Difference between revisions

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*1. Self-consistent calculation with symmetry switched on (ISYM=2)
*1. Self-consistent calculation with symmetry switched on (ISYM=2)
*2. Recalculation of the partial charge density with symmetry switched off (ISYM=0)
*2. Recalculation of the partial charge density with symmetry switched off (ISYM=0)
To avoid unnecessary large {{TAG|WAVECAR}} files it recommended to set {{TAG|LWAVE}}=.FALSE. in step 2.  
To avoid unnecessary large {{TAG|WAVECAR}} files it recommended to set {{TAG|LWAVE}}=.FALSE. in step 2
 
If LORBIT is set the partial charge densities can be found in the {{TAGBL|OUTCAR}}
total charge   
# of ion      s      p      d      tot
------------------------------------------
    1        1.514  0.000  0.000  1.514
    2        0.123  0.345  0.000  0.468
Here the first column corresponds to the ion index <math>\alpha</math>, the s, p, d,... columns correspond to the partial charges for <math>l=0,1,2,\cdots</math> defined as
 
<math>\rho_{\alpha l}=\frac{1}{N_{\bf k}} \sum_{n{\bf k}}f_{n{\bf k}} \sum_{m=-l}^{l}|\langle Y_{lm}^{\alpha}|\phi_{n\mathbf{k}}\rangle|^2
</math>
 
The <math>\langle Y_{lm}^{\alpha}|\phi_{n\mathbf{k}}\rangle</math> are obtained from the projection of the (occupied) wavefunctions <math>|\phi_{n{\bf k}}\rangle</math> onto spherical harmonics that are non zero within spheres of a radius {{TAG|RWIGS}} centered at ion <math>\alpha</math> and
the last column is the sum <math>\sum_{l}\rho_{\alpha l}</math>.
 
Note that depending on the system an "f" column can be found as well.
 
In case of collinear calculations ({{TAGBL|ISPIN}}=2) the magnetization densities are written to the {{TAGBL|OUTCAR}}
magnetization (x)
 
# of ion      s      p      d      tot
------------------------------------------
    1        0.000  0.000  0.000  0.000
    2        0.000  0.245  0.000  0.245
 
Here the magnetization density (projection axis is the z-axis) is calculated from the difference in the up and down spin channel <math>m^{\alpha l}_z = \rho_{\alpha l}^{\uparrow}-\rho_{\alpha l}^{\downarrow}
</math>
 
In case of non-collinear calculations ({{TAGBL|LNONCOLLINEAR}}=.TRUE.) the lines after "total charge" correspond to the charge density differences in the diagonal of the density
<math>
\rho_{\alpha l} =
 
</math>
 
 
the lines after "magnetization (x)" correspond to the partial magnetization density projected onto the x direction and two additional entries "magnetization (y)", "magnetization (z)" are written for the y and z direction.


== Related Tags and Sections ==
== Related Tags and Sections ==

Revision as of 16:37, 8 January 2019

LORBIT = 0 | 1 | 2 | 5 | 10 | 11 | 12
Default: LORBIT = None 

Description: LORBIT, together with an appropriate RWIGS, determines whether the PROCAR or PROOUT files are written.


LORBIT RWIGS tag files written
0 required DOSCAR and PROCAR
1 required DOSCAR and lm-decomposed PROCAR
2 required DOSCAR and lm-decomposed PROCAR + phase factors
5 required DOSCAR and PROOUT
10 ignored DOSCAR and PROCAR
11 ignored DOSCAR and lm-decomposed PROCAR
12 ignored DOSCAR and lm-decomposed PROCAR + phase factors

Remark:

For LORBIT = 11 and ISYM = 2 the partial charge densities are not correctly symmetrized and can result in different charges for symmetrically equivalent partial charge densities. This issue if fixed as of version >=6. For older versions of vasp a two-step procedure is recommended:

  • 1. Self-consistent calculation with symmetry switched on (ISYM=2)
  • 2. Recalculation of the partial charge density with symmetry switched off (ISYM=0)

To avoid unnecessary large WAVECAR files it recommended to set LWAVE=.FALSE. in step 2

If LORBIT is set the partial charge densities can be found in the OUTCAR

total charge     

# of ion       s       p       d       tot
------------------------------------------
    1        1.514   0.000   0.000   1.514
    2        0.123   0.345   0.000   0.468

Here the first column corresponds to the ion index [math]\displaystyle{ \alpha }[/math], the s, p, d,... columns correspond to the partial charges for [math]\displaystyle{ l=0,1,2,\cdots }[/math] defined as

[math]\displaystyle{ \rho_{\alpha l}=\frac{1}{N_{\bf k}} \sum_{n{\bf k}}f_{n{\bf k}} \sum_{m=-l}^{l}|\langle Y_{lm}^{\alpha}|\phi_{n\mathbf{k}}\rangle|^2 }[/math]

The [math]\displaystyle{ \langle Y_{lm}^{\alpha}|\phi_{n\mathbf{k}}\rangle }[/math] are obtained from the projection of the (occupied) wavefunctions [math]\displaystyle{ |\phi_{n{\bf k}}\rangle }[/math] onto spherical harmonics that are non zero within spheres of a radius RWIGS centered at ion [math]\displaystyle{ \alpha }[/math] and the last column is the sum [math]\displaystyle{ \sum_{l}\rho_{\alpha l} }[/math].

Note that depending on the system an "f" column can be found as well.

In case of collinear calculations (ISPIN=2) the magnetization densities are written to the OUTCAR

magnetization (x)
 
# of ion       s       p       d       tot
------------------------------------------
    1        0.000   0.000   0.000   0.000
    2        0.000   0.245   0.000   0.245

Here the magnetization density (projection axis is the z-axis) is calculated from the difference in the up and down spin channel [math]\displaystyle{ m^{\alpha l}_z = \rho_{\alpha l}^{\uparrow}-\rho_{\alpha l}^{\downarrow} }[/math]

In case of non-collinear calculations (LNONCOLLINEAR=.TRUE.) the lines after "total charge" correspond to the charge density differences in the diagonal of the density [math]\displaystyle{ \rho_{\alpha l} = }[/math]


the lines after "magnetization (x)" correspond to the partial magnetization density projected onto the x direction and two additional entries "magnetization (y)", "magnetization (z)" are written for the y and z direction.

Related Tags and Sections

RWIGS, PROCAR, PROOUT, DOSCAR

Examples that use this tag


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