Concentrational Mana Regeneration (3.5e Feat)
From D&D Wiki
concentrational mana regen [Magic feat]
allows concentration check to regen minor spell points
Prerequisite: spell points, caster level 5th
Benefit: user can make a concentraion check and if successful [ dc 15+ caster level] they can regen their casting stats amount of spell points, uses a full round action
Normal: user only regens per hour or long rest.