RestartFromTrajectory

class RestartFromTrajectory(trajectory_filename=None, object_id=None, restore_optimizer_state=None)

Class for restarting a geometry optimization from a previously saved trajectory.

Parameters:

  • trajectory_filename (str) – The filename used to look for the restart trajectory.

  • object_id (str) – The ID of the object in the file. Can only be specified together with a trajectory_filename.

  • restore_optimizer_state (bool) – Whether to restart using the state of the optimizer method object as well as the atomic positions.
    Default: True if the optimizer method object is present on the trajectory and compatible with the new optimizer method, False otherwise.

objectId()
Returns:

The object ID of the restart trajectory.

Return type:

str | None

restoreOptimizerState()
Returns:

Whether to restart using the state of the optimizer method object.

Return type:

bool | None

trajectoryFilename()
Returns:

The filename used to look for the restart trajectory.

Return type:

str | None

uniqueString()

Return a unique string representing the state of the object.

Notes

The RestartFromTrajectory class is intended to facilitate restarts of OptimizeGeometry() and OptimizeNudgedElasticBand(), as well as other objects which accept OptimizeGeometryParameters, using an existing trajectory file.

If trajectory_filename is not specified in RestartFromTrajectory, the filename of the current optimization object will be used to search for a compatible trajectory to restart from. In case no trajectory can be found, the restart behavior falls back to NoRestart.

If specified, the object_id parameter will determine the object in the file that is used for restart. For OptimizeNudgedElasticBand() the specified object_id is treated as prefix and all matching NudgedElasticBand objects in the file are searched for. The one with the highest suffix is used. If the object_id parameter is not specified, the trajectory_object_id in OptimizeGeometry() or OptimizeNudgedElasticBand() will be used if specified there. Otherwise the trajectory file will be searched for all objects matching the expected type with numbered IDs, and the highest one will be used. In case no matching object can be found, the restart behavior falls back to NoRestart.

Before restarting from a given object, the simulations are checked for consistency, including elements, type of configuration, constraints, optimizer method, and calculator (only for NEB). If the consistency check fails, a warning is printed to the log file and the restart behavior falls back to NoRestart.