Question

What does Density Functional Theory (DFT) enable someone to do that you cannot with group theory. I know that group theory enables you to assign a point group to a molecule which represents its overall symmetry, assign translational, rotational, and vibrational modes, and determine which of these vibrational modes are IR or Raman active. What does DFT offer that group theory doesn't?

Answer 1

A direct product of DFT(density functional theory) is the electronic structure of a molecule . Group theory does not provide any information about the electronic structure of a molecule.

Using DFT we can instantly find the occupation numbers of the different atomic orbitals and the distribution of electrons in those orbitals of the molecule. It is also possible to determine the different energy states of a molecule and also it helps us to determine the energies of the excited states of the molecules.

DFT helps to understand kinetics and thermodynamics outcomes of the molecules. It can be used to determine the energy of a given system and also helps to do molecular dynamics, with which it is possible to observe the interactions between atomic systems.