Classical Helium Model is a three-body problem simulation to help you with your studies. Classical Helium Model is an example of a three-body problem that is similar to the gravitational three-body problem of a heavy sun and two light planets. The important difference is that the helium atom's two electrons repel one another, unlike the planetary case where the intraplanetary interaction is attractive.

The EJS Classical Helium Model was created using the Easy Java Simulations (Ejs) modeling tool. It is distributed as a ready-to-run (compiled) Java archive. Double clicking the ejs_mech_orbits_ClassicalHelium.jar file will run the program if Java is installed.

Because the electrons are sometimes very close to the nucleus, their acceleration can become very large, and a very small time step it is required. It is not efficient to use the same small time step throughout the simulation and instead a variable time step or an adaptive step size algorithm is suggested. An adaptive step size algorithm can be used with any standard numerical algorithm for solving differential equations. The RK45 algorithm described in is adaptive and is a good all-around choice for these types of problems.

Requirements:
* Java

The license of this software is Freeware, you can free download and free use this graphing software.