Particles in a three-dimensional spherically symmetric potential

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Disclaimer: I lay no claim to the originality of the basic ideas expounded here. Its distinctness lies more in its scope and in the detail of its exposition.

Particles in a 3D Symmetric Potential

In a three dimensional spherically symmetric potential alt the time-independent Schrodinger equation for stationary states of energy E is

alt

This Schrodinger equation in polar coordinates is expressed by

alt

We multiply this equation by alt

alt

We then, substitute this wavefunction,

alt

We have

alt

Note that the left side is only a function of r, meaning we can shift the partial derivative to a total derivative,

alt

On the other hand, the left side is a function of $\theta$ and $\varphi$ only,

alt

Note also that they must be equal to a constant because of the different variable dependence. They must be equal to the same constant.

Remember this equation:

alt

Thus, the angular part can be written as,

alt

From the previous section, we've encountered this operator and found that its eigenvalue spectrum are

alt

Now, let's consider the radial part of the equation,

alt

We can substitute our value of alt into this equation,

alt

Particles in a three-dimensional spherically symmetric potential | Ecency