Article 900

If the only survivor is the widow or widower, she or he shall be entitled to one-half of the hereditary estate of the deceased spouse, and the testator may freely dispose of the other half. (837a)

If the marriage between the surviving spouse and the testator was solemnized in articulo mortis, and the testator died within three months from the time of the marriage, the legitime of the surviving spouse as the sole heir shall be one-third of the hereditary estate, except when they have been living as husband and wife for more than five years. In the latter case, the legitime of the surviving spouse shall be that specified in the preceding paragraph. (n)