A latent variable model is a statistical model that relates a set of variables (so-called manifest variables) to a set of latent variables.
DEFINITION of 'Functional Obsolescence'. A reduction in the usefulness or desirability of an object because of an outdated design feature, usually one that cannot be easily changed.The term is commonly used in real estate, but has a wide application.Next Up. reduction in the usefulness or desirability of an object because of an outdated design feature, usually one that cannot be easily changed. The term is commonly used in real estate, but has a wide application. Next Up.
Our most basic approximation does just this. It is called the Born-Oppenheimer approximation. A functional is a function of a function. In DFT the functional is the electron density which is a function of space and time.The electron density is used in DFT as the fundamental property unlike Hartree-Fock theory which deals directly with the many-body wavefunction.n this case the total ground state energy of a many-electron system is a functional of the density. So, if we know the electron density functional, we know the total energy of our system. By focusing on the electron density it is possible to derive an effective one-electron-type Schroedinger schrÃ¶dinger. equation