# Committor simulations

The {mod}`aimmd.distributed` contains a class to perform committor simulations for an arbitrary number of configurations and trials in parallel.
The {class}`CommittorSimulation <aimmd.distributed.CommittorSimulation>` allows to perform committor trials in one direction only, or optionally, will also perform for every trial a propagation with inverted momenta at the shooting point.
This feature can be particularly useful to generate initial transitions as input for a transition path sampling simulation.

The input configurations for the {class}`CommittorSimulation <aimmd.distributed.CommittorSimulation>` are expected to be wrapped as {class}`CommittorConfiguration <aimmd.distributed.CommittorConfiguration>` dataclasses.
The MD engine and other propagation options for the trials are defined (potentially on a per-configuration basis) via the dataclass {class}`CommittorEngineSpec <aimmd.distributed.CommittorEngineSpec>`.
Note that a number of options to the {class}`CommittorSimulation <aimmd.distributed.CommittorSimulation>` can be specified on a per-configuration basis (in addition to the {class}`CommittorEngineSpec <aimmd.distributed.CommittorEngineSpec>`), enabling users to easily bundle multiple related committor simulations into {class}`CommittorSimulation <aimmd.distributed.CommittorSimulation>`, e.g., using different temperatures, pressures, or even slightly different (or very different, but this is not recommended except if you are way too organized, and then you would not [dare to] do it...) molecular systems.
See the docstring of the {class}`CommittorSimulation <aimmd.distributed.CommittorSimulation>` for more.

```{seealso}
The example notebook on the {doc}`CommittorSimulation </examples_link/distributed/CommittorSimulation>`, which shows how to perform a committor simulation on capped alanine dipeptide.
```

```{eval-rst}
.. autoclass:: aimmd.distributed.CommittorConfiguration

.. autoclass:: aimmd.distributed.CommittorEngineSpec

.. autoclass:: aimmd.distributed.CommittorSimulation
    :class-doc-from: both
    :member-order: groupwise
    :members:
    :inherited-members:
```