20 CFR §725.214

1. (a)The courts of the State in which the miner was domiciled (see § 725.231) at the time of his or her death would find that the individual and the miner were validly married; or
2. (b)The courts of the State in which the miner was domiciled (see § 725.231) at the time of the miner's death would find that the individual was the miner's surviving spouse; or
3. (c)Under State law, such individual would have the right of the spouse to share in the miner's intestate personal property; or
4. (d)Such individual went through a marriage ceremony with the miner, resulting in a purported marriage between them which, but for a legal impediment (see § 725.230), would have been a valid marriage, unless such individual entered into the purported marriage with knowledge that it was not a valid marriage, or if such individual and the miner were not living in the same household at the time of the miner's death.