How do I write a full Schrodinger equation, pre-approximation, for a mixture? Let's say 75% H2 and 25% He by number of particles. I already know the form and very basic applications of the Schrodinger equation and the Hamiltonian. What I want to know is, the specifics, such as how to specify the potentials. I'd like to be able to write the full equation. Does this PDF specify the potentials properly: http://www.phys.ubbcluj.ro/~vchis/cursuri/cspm/course2.pdf If so, then what do we have to do to this Hamiltonian to set up an equation that is ready for us to solve in principle? I'm aware that exactly solving such a thing isn't possible, I just want to see the form.