This method of quantifying orbital contribution as a linear combination of atomic orbitals is used in computational chemistry. A larger coefficient means that the orbital basis is composed more of that particular contributing atomic orbital-hence, the molecular orbital is best characterized by that type. The variational principle is a mathematical technique used in quantum mechanics to build up the coefficients of each atomic orbital basis. One may determine c ij coefficients numerically by substituting this equation into the Schrödinger equation and applying the variational principle. It is assumed that the molecular orbital wave function ψ j can be written as a simple weighted sum of the n constituent atomic orbitals χ i, according to the following equation: In the LCAO method, each molecule has a set of molecular orbitals. Linear combination of atomic orbitals (LCAO) method Molecular orbital theory and valence bond theory are the foundational theories of quantum chemistry. These approximations are made by applying the density functional theory (DFT) or Hartree–Fock (HF) models to the Schrödinger equation. Molecular orbital theory revolutionized the study of chemical bonding by approximating the states of bonded electrons-the molecular orbitals-as linear combinations of atomic orbitals (LCAO). Quantum mechanics describes the spatial and energetic properties of electrons as molecular orbitals that surround two or more atoms in a molecule and contain valence electrons between atoms.
In molecular orbital theory, electrons in a molecule are not assigned to individual chemical bonds between atoms, but are treated as moving under the influence of the atomic nuclei in the whole molecule. It was proposed early in the 20th century. The development of practical methods to describe Feshbach resonance enhanced diatomic collisions as well as two- and three-body bound states in the tight microtraps of optical lattices.In chemistry, molecular orbital theory (MO theory or MOT) is a method for describing the electronic structure of molecules using quantum mechanics.The description of atom-molecule coherence phenomena in Bose-Einstein condensates.Molecular formation via magnetic field tunable interatomic interactions as well as photoassociation.Our ongoing research includes topics such as: The applications of our research are far reaching they range from precise studies of two- and few-body ultracold collisions to the many-body physics of Cooper pairing of Fermions. The aim of our research is to theoretically understand the dynamics of the association of molecules and its interplay with the bulk motion in trapped Bose-Einstein condensates and quantum degenerate two component Fermi gases. The formation of ultracold molecules is a new and rapidly developing area in the physics of quantum degenerate gases. The molecular theory group also works alongside the Quantemol company producing software model electron polyatomic molecule interactions for a variety of applications including plasma physics. Calculations by the molecular theory group led directly to the detection of water in the atmosphere of the hot Jupiter-like planet in 2007, the first molecule detected on an extra solar planet. The image on the left shows an artists impression of extra solar planet HD189733b.