Density-functional theory. Ab initio method not based upon a wavefunction. Instead, the energy is computed as a functional of the electron density. Sometimes called Kohn-Sham theory. The correct functional has not yet been found, but many approximations are in use.
(Density Functional Theory) ab initio electronic method from solid state physics. Tries to find best approximate functional to calculate energy from e- density. Scales as 2nd power times a large number. Static correlation built in. Not variational. Believed to be size consistent.
Design-for-Testability. The insertion into an SoC design of non-functional logic used to exercise functional logic, and extract subsequent data, in order to determine the existence and location of any logic faults introduced during manufacturing.