Source code for clease.montecarlo.observers.sgc_observer

import numpy as np
import attr
from clease.calculator import Clease
from clease.montecarlo.averager import Averager
from clease.datastructures.mc_step import MCStep
from .mc_observer import MCObserver

class SGCQuantities:
    """Container for observed quantities in the SGCObserver"""

    energy: Averager = attr.field()
    energy_sq: Averager = attr.field()
    singlets: np.ndarray = attr.field()
    singlets_sq: np.ndarray = attr.field()
    singl_eng: np.ndarray = attr.field()
    counter: int = attr.field(default=0)

    def reset(self) -> None:
        self.counter = 0
        self.singlets[:] = 0.0
        self.singlets_sq[:] = 0.0
        self.singl_eng[:] = 0.0

[docs]class SGCObserver(MCObserver): """ Observer mainly intended to track additional quantities needed when running SGC Monte Carlo. This observer has to be executed on every MC step. Parameters: calc: `clease.calculators.Clease` Clease calculator observe_singlets: bool Whether the singlet values of the calculator are measured during each observation. Measuring singlets is slightly more expensive, so this is disabled by default. """ name = "SGCObersver" def __init__(self, calc: Clease, observe_singlets: bool = False): self.observe_singlets = observe_singlets super().__init__() self.calc = calc initial_energy = calc.get_potential_energy() n_singlets = len(self.calc.get_singlets()) self.quantities = SGCQuantities( energy=Averager(ref_value=initial_energy), energy_sq=Averager(ref_value=initial_energy**2), singlets=np.zeros(n_singlets, dtype=np.float64), singlets_sq=np.zeros(n_singlets, dtype=np.float64), singl_eng=np.zeros(n_singlets, dtype=np.float64), )
[docs] def reset(self): """Reset all variables to zero.""" self.quantities.reset()
[docs] def get_current_energy(self) -> float: """Return the current energy of the attached calculator object.""" return self.calc.results["energy"]
[docs] def observe_step(self, mc_step: MCStep): """Update all SGC parameters.""" # Reference to avoid self. lookup multiple times quantities = self.quantities E = self.get_current_energy() quantities.counter += 1 += E quantities.energy_sq += E * E if self.observe_singlets: # Only perform the singlet observations if requested. new_singlets = self.calc.get_singlets() quantities.singlets += new_singlets quantities.singlets_sq += new_singlets * new_singlets quantities.singl_eng += new_singlets * E
@property def energy(self): return @property def energy_sq(self): return self.quantities.energy_sq @property def singlets(self): return self.quantities.singlets @property def singl_eng(self): return self.quantities.singl_eng @property def counter(self): return self.quantities.counter
[docs] def interval_ok(self, interval): return interval == 1