You can focus your powers to imbue a melee weapon with psionic force.

Prerequisite: Psionic Ability

Benefit: You can imbue a melee weapon with a field of psionic energy that enhances its striking power. The weapon does an additional 1d8 points of damage per six character levels you possess (round down with a minimum of +1d8). You can imbue a psionic weapon (created by the Psionic Weapon skill) and this damage bonus stacks with the weapon’s normal damage. An imbued weapon can also block a psionic weapon, unlike most physical weapons.