What is the Schrodinger equation, and how is it used?

Asked by: Zane Goodwin

Answer

At the beginning of the twentieth century, experimental evidence suggested that atomic
particles were also wave-like in nature. For example, electrons were found to give
diffraction patterns when passed through a double slit in a similar way to light waves.
Therefore, it was reasonable to assume that a wave equation could explain the behaviour
of atomic particles.

Schrodinger was the first person to write down such a wave equation.
Much discussion then centred on what the equation meant. The eigenvalues of the wave
equation were shown to be equal to the energy levels of the quantum mechanical system,
and the best test of the equation was when it was used to solve for the energy levels of
the Hydrogen atom, and the energy levels were found to be in accord with Rydberg's Law.

It was initially much less obvious what the wavefunction of the equation was. After much
debate, the wavefunction is now accepted to be a probability distribution. The
Schrodinger equation is used to find the allowed energy levels of quantum mechanical
systems (such as atoms, or transistors). The associated wavefunction gives the
probability of finding the particle at a certain position.
Answered by: Ian Taylor, Ph.D., Theoretical Physics (Cambridge), PhD (Durham), UK

The Shrodinger equation is:

The solution to this equation is a wave that describes the quantum aspects of a system.
However, physically interpreting the wave is one of the main philosophical problems of
quantum mechanics.

The solution to the equation is based on the method of Eigen Values devised by Fourier.
This is where any mathematical function is expressed as the sum of an infinite series of
other periodic functions. The trick is to find the correct functions that have the right
amplitudes so that when added together by superposition they give the desired solution.

So, the solution to Schrondinger's equation, the wave function for the system, was
replaced by the wave functions of the individual series, natural harmonics of each other,
an infinite series. Shrodinger has discovered that the replacement waves described the
individual states of the quantum system and their amplitudes gave the relative importance
of that state to the whole system.

Schrodinger's equation shows all of the wave like properties of matter and was one of
greatest achievements of 20th century science.

It is used in physics and most of chemistry to deal with problems about the atomic
structure of matter. It is an extremely powerful mathematical tool and the whole basis of
wave mechanics.
Answered by: Simon Hooks, Physics A-Level Student, Gosport, UK

The Schrodinger equation is the name of the basic non-relativistic wave equation used in
one version of quantum mechanics to describe the behaviour of a particle in a field of
force. There is the time dependant equation used for describing progressive waves,
applicable to the motion of free particles. And the time independent form of this
equation used for describing standing waves.

Schrodinger's time-independent equation can be solved analytically for a number of simple
systems. The time-dependant equation is of the first order in time but of the second
order with respect to the co-ordinates, hence it is not consistent with relativity. The
solutions for bound systems give three quantum numbers, corresponding to three
co-ordinates, and an approximate relativistic correction is possible by including fourth
spin quantum number.
Answered by: Dan Summons, Physics Undergrad Student, UOS, Souhampton

'Every creative act involves ... a new innocence of perception, liberated from the cataract of accepted belief.'