CMBJ: Difference between revisions

Latest revision as of 10:25, 15 February 2023

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

Description: defines the $c$ parameter in the MBJ potential.

The CMBJ tag can be set in the following ways:

Specify a constant that is used at every point of space $\mathbf{r}$ $\mathbf{r}$
```
CMBJ = c
```

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

If CMBJ is not set, $c$ is calculated at each electronic step as the average of $\left\vert\nabla n\right\vert/n$ in the unit cell, as explained in the description of the METAGGA tag.

References

@@ Line 9: / Line 9: @@
 *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, <math>c</math> is calculated at each electronic step as the average of <math>\nabla n/n</math> in the unit cell, as explained in the description of the {{TAG|METAGGA}} tag.
+If {{TAG|CMBJ}} is not set, <math>c</math> is calculated at each electronic step as the average of <math>\left\vert\nabla n\right\vert/n</math> in the unit cell, as explained in the description of the {{TAG|METAGGA}} tag.
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