**Molecular Orbital Theory**

In chemistry, **molecular orbital (MO) theory** is a method for determining molecular structure in which electrons are not assigned to individual bonds between atoms, but are treated as moving under the influence of the nuclei in the whole molecule. In this theory, each molecule has a set of molecular orbitals, in which it is assumed that the molecular orbital wave function *ψ _{j}* may be written as a simple weighted sum of the n constituent atomic orbitals

*χ*, according to the following equation:

_{i}The *c _{ij}* coefficients may be determined numerically by substitution of this equation into the Schrödinger equation and application of the variational principle. This method is called the linear combination of atomic orbitals (LCAO) approximation and is used in computational chemistry. An additional unitary transformation can be applied on the system to accelerate the convergence in some computational schemes. Molecular orbital theory was seen as a competitor to valence bond theory in the 1930s, before it was realized that the two methods are closely related and that when extended they become equivalent.

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**Molecular Orbital Theory**

... F−Xe−F subunit is described by a set of three

**molecular orbitals**(MOs) derived from colinear p-

**orbitals**on each atom ... The Xe−F bonds result from the combination of a filled p

**orbital**in the central atom (Xe) with two half-filled p

**orbitals**on the axial atoms (F), resulting in a filled bonding

**orbital**, a filled non-bond ... The bond order for each Xe-F bonds is 1/2, since the only bonding

**orbital**is delocalized over the two Xe-F bonds ...

**Molecular Orbital Theory**- Overview

...

**Molecular orbital**(MO)

**theory**uses a linear combination of atomic

**orbitals**(LCAO) to represent

**molecular orbitals**involving the whole molecule ... These are often divided into bonding

**orbitals**, anti-bonding

**orbitals**, and non-bonding

**orbitals**... A

**molecular orbital**is merely a Schrödinger

**orbital**that includes several, but often only two, nuclei ...

### Famous quotes containing the word theory:

“Frankly, these days, without a *theory* to go with it, I can’t see a painting.”

—Tom Wolfe (b. 1931)