# fix drude command

## Syntax

    fix ID group-ID drude flag1 flag2 ... flagN

-   ID, group-ID are documented in [fix](fix) command
-   drude = style name of this fix command
-   flag1 flag2 \... flagN = Drude flag for each atom type (1 to N) in
    the system

## Examples

``` LAMMPS
fix 1 all drude 1 1 0 1 0 2 2 2
fix 1 all drude C C N C N D D D
```

Example input scripts available: examples/PACKAGES/drude

## Description

Assign each atom type in the system to be one of 3 kinds of atoms within
the Drude polarization model. This fix is designed to be used with the
[thermalized Drude oscillator model](Howto_drude). Polarizable models in
LAMMPS are described on the [Howto polarizable](Howto_polarizable) doc
page.

The three possible types can be designated with an integer (0,1,2) or
capital letter (N,C,D):

-   0 or N = non-polarizable atom (not part of Drude model)
-   1 or C = Drude core
-   2 or D = Drude electron

## Restrictions

This fix should be invoked before any other commands that implement the
Drude oscillator model, such as [fix
langevin/drude](fix_langevin_drude), [fix tgnvt/drude](fix_tgnh_drude),
[fix drude/transform](fix_drude_transform), [compute
temp/drude](compute_temp_drude), [pair_style thole](pair_thole).

## Related commands

[fix langevin/drude](fix_langevin_drude), [fix
tgnvt/drude](fix_tgnh_drude), [fix
drude/transform](fix_drude_transform), [compute
temp/drude](compute_temp_drude), [pair_style thole](pair_thole)

## Default

none