| 57 |
|
/*! The field is applied as an external perturbation. The user specifies |
| 58 |
|
|
| 59 |
|
\code{.unparsed} |
| 60 |
< |
uniformField = (ex, ey, ez); |
| 60 |
> |
uniformField = (a, b, c); |
| 61 |
|
\endcode |
| 62 |
|
|
| 63 |
< |
in the .md file where the values of ex, ey, and ez are in units of |
| 63 |
> |
in the .md file where the values of a, b, and c are in units of |
| 64 |
|
\f$ V / \AA \f$ |
| 65 |
|
|
| 66 |
+ |
The electrostatic potential corresponding to this uniform field is |
| 67 |
+ |
|
| 68 |
+ |
\f$ \phi(\mathbf{r}) = - a x - b y - c z \f$ |
| 69 |
+ |
|
| 70 |
+ |
which grows unbounded and is not periodic. For these reasons, |
| 71 |
+ |
care should be taken in using a Uniform field with point charges. |
| 72 |
+ |
|
| 73 |
+ |
The field itself is |
| 74 |
+ |
|
| 75 |
+ |
\f$ \mathbf{E} = \left( \array{c} a \\ b \\ c \end{array} \right) \f$ |
| 76 |
+ |
|
| 77 |
|
The external field applies a force on charged atoms, \f$ \mathbf{F} |
| 78 |
|
= C \mathbf{E} \f$. For dipolar atoms, the field applies both a |
| 79 |
|
potential, \f$ U = - \mathbf{D} \cdot \mathbf{E} \f$ and a torque, |
