Thanks Paolo, > try to set the charge grid to 24 (nr1=24,nr2=24,nr3=24 in > namelist system) and see if it makes a difference The difference in total energies becomes less than 1e-6. Lazaro -- Lazaro Calderin Department of Physics Queen's University Kingston, Ontario K7L 3N6, Canada +1 613 533 6000 ext 74811 calderin at physics.queensu.ca