def METHOD_NAME(self) -> VibrationalOp:
    """Returns the second quantized vibrational energy operator.
    Returns:
        A ``dict`` of ``VibrationalOp`` objects.
    """
    truncated_integrals = self.vibrational_integrals
    if self.truncation_order is not None:
        truncated_integrals = VibrationalIntegrals(
            {
                key: value
                for key, value in self.vibrational_integrals.items()
                if len(key) <= 3 * self.truncation_order
            },
            validate=False,
        )
    return VibrationalOp.from_polynomial_tensor(truncated_integrals)