Whether the calculation has converged
        
        Returns: Property where "scalar" is a boolean indicating

def is_converged(self):
        '''Whether the calculation has converged
        
        Returns: Property where "scalar" is a boolean indicating
        '''

        # Check for cached result
        if self._converged is None:
            self._converged = self._is_converged()
        return Property(scalars=[Scalar(value=self._converged)])