CMBJ: Difference between revisions

Revision as of 19:20, 7 April 2022

CMBJ = [real (array)]
Default: CMBJ = calculated self-consistently

Description: defines the [math]\displaystyle{ c }[/math] parameter in the MBJ potential.

The CMBJ tag can be set in the following ways:

Specify a constant
```
CMBJ = c
```

Specify one entry per atomic type
```
CMBJ = c_1 c_2 .. c_n
```
where the order and number [math]\displaystyle{ n }[/math] is in accordance with atomic types in your POSCAR file. The MBJ exchange potential at a point [math]\displaystyle{ \mathbf{r} }[/math] will then be calculated using the parameter [math]\displaystyle{ c_{i} }[/math] belonging to the atomic species of the atomic site nearest to [math]\displaystyle{ \mathbf{r} }[/math].

If CMBJ is not set, it is calculated at each electronic step as the average of [math]\displaystyle{ \nabla n_{\sigma} }[/math] in the unit cell, as explained in the description of the METAGGA tag.

Related Tags and Sections

METAGGA, CMBJA, CMBJB, LASPH, LMAXTAU, LMIXTAU

Examples that use this tag

References

Contents

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 The {{TAG|CMBJ}} tag can be set in the following ways:
-*One may specify one entry per atomic type<pre>CMBJ = c_1 c_2 .. c_n</pre> where the order and number <math>n</math> is in accordance with atomic types in your {{FILE|POSCAR}} file. The MBJ exchange potential at a point <math>\mathbf{r}</math> will then be calculated using the parameter <math>c_{i}</math> belonging to the atomic species of the atomic site nearest to <math>\mathbf{r}</math>.
+*Specify a constant<pre>CMBJ = c</pre>
-*Specify a constant<pre>CMBJ = c</pre>
+*Specify one entry per atomic type<pre>CMBJ = c_1 c_2 .. c_n</pre> where the order and number <math>n</math> is in accordance with atomic types in your {{FILE|POSCAR}} file. The MBJ exchange potential at a point <math>\mathbf{r}</math> will then be calculated using the parameter <math>c_{i}</math> belonging to the atomic species of the atomic site nearest to <math>\mathbf{r}</math>.
 If {{TAG|CMBJ}} is not set, it is calculated at each electronic step as the average of <math>\nabla n_{\sigma}</math> in the unit cell, as explained in the description of the {{TAG|METAGGA}} tag.