Some quick explanations of the applet's use:

Left hand buttons

• input: shows the input parameter page
• clear plot: right hand plot will show the wavefunction as a function of radial distance from the nucleus
• clear scanplot: right hand plot will show the sign of the wavefunction (red = positive) as a function of radial distance from the nucleus while scanning thru the electron's energy
• clear ritzplot: right hand plot will show the value (or +1, -1) of the wavefunction at the last radial distance, while scanning thru the electron energy

Left hand panel = model input parameters

• radial step: integration stepwidth
• angular momentum: of the electron
• (min.) energy: lower bound for energy scan
• no.of energies: number of values in energy scan
• max.energy: upper bound for energy scan
• max.radius: the maximum radial distance from the nucleus up to which the wavefunctions are computed
• R(0)=: initial value of wavefunction (at the nucleus)
• R'(0)=: initial radial derivative of wavefunction
• hitting the enter key while in a textfield - after changing the parameter value, for example - will start the next simulation

Right hand buttons:

• start: start the simulation with the parameters as given on the left hand panel
• stop: halts the current simulation
• resume: continues with the halting simulation
• drag&zoom: click the button, then drag the mouse over that region of the plot which you want to zoom in. Then re-run the simulation
• unZoom: brings back the full view of the plot, but you have to re-run to restore the curve(s)
• clicking on the plot surface will display the x and y-values of that point