California Code, Probate Code - PROB § 671

(a) Unless the creating instrument or the powerholder, in writing, manifests a contrary intent, where the powerholder dies without having exercised an imperative power of appointment either in whole or in part, the persons designated as permissible appointees take equally of the property not already appointed. Where the creating instrument establishes a minimum distribution requirement that is not satisfied by an equal division of the property not already appointed, the appointees who have received a partial appointment are required to return a pro rata portion of the property they would otherwise be entitled to receive in an amount sufficient to meet the minimum distribution requirement.

(b) Where an imperative power of appointment has been exercised defectively, either in whole or in part, its proper execution may be adjudged in favor of the person intended to be benefited by the defective exercise.

(c) Where an imperative power of appointment has been created so that it confers on a person a right to have the power exercised in the person's favor, the proper exercise of the power can be compelled in favor of the person, or the person's assigns, creditors, guardian, or conservator.