Home › Forums › density functional theory › functions and functionals › Example functional This topic has 0 replies, 1 voice, and was last updated 2 months, 2 weeks ago by Maarten Carrette. Viewing 1 post (of 1 total) Author Posts October 1, 2024 at 12:03 pm #11417 Maarten CarretteParticipant Taking the integral of a function f(x) with borders x_1 and x_2 is a functional because it takes f(x) as input and gives a number as the output. Author Posts Viewing 1 post (of 1 total) You must be logged in to reply to this topic. Log In Username: Password: Keep me signed in Log In