Sunday, March 15, 2009

Hartee Fock

n computational physics and computational chemistry, the Hartree-Fock (HF) method is an approximate method for the determination of the ground-state wavefunction and ground-state energy of a quantum many-body system.

Metoda Hartee Fock ada

The Hartree-Fock method assumes that the exact, N-body wavefunction of the system can be approximated by a single Slater determinant (in the case where the particles are fermions) or by a single permanent (in the case of bosons) of N spin-orbitals. By invoking the variational principle, one can derive a set of N-coupled equations for the N spin orbitals. Solution of these equations yields the Hartree-Fock wavefunction and energy of the system, which are approximations of the exact ones.

The Hartree-Fock method finds its typical application in the solution of the electronic Schrödinger equation of atoms, molecules, and solids but it has also found widespread use in nuclear physics. (See Hartree-Fock-Bogolyubov for a discussion of its application in nuclear structure theory.) The rest of this article will focus on applications in electronic structure theory.