Source code for mchammer.observers.cluster_expansion_observer

from ase import Atoms
from icet import ClusterExpansion
from mchammer.observers.base_observer import BaseObserver

[docs]class ClusterExpansionObserver(BaseObserver): """ This class represents a cluster expansion (CE) observer. A CE observer allows to compute a property described by a CE along the trajectory sampled by a Monte Carlo (MC) simulation. In general this CE differs from the CE that is used to generate the trajectory. For example in a canonical MC simulation the latter would usually represent an energy (total or mixing energy) whereas the former CE(s) could map lattice constant or band gap. Parameters ---------- cluster_expansion : :class:`icet.ClusterExpansion` cluster expansion model to be used for observation tag : str human readable observer name (default: `ClusterExpansionObserver`) interval : int observation interval during the Monte Carlo simulation Attributes ---------- tag : str name of observer interval : int the observation interval, defaults to None meaning that if the observer is used in a Monte Carlo simulation, then the Ensemble object will set the interval. """ def __init__(self, cluster_expansion: ClusterExpansion, interval: int = None, tag: str = 'ClusterExpansionObserver') -> None: super().__init__(interval=interval, return_type=float, tag=tag) self._cluster_expansion = cluster_expansion
[docs] def get_observable(self, structure: Atoms) -> float: """ Returns the value of the property from a cluster expansion model for a given atomic configuration. Parameters ---------- structure input atomic structure. """ return self._cluster_expansion.predict(structure)