Typically referring to the time-independent Schrodinger Equation:
which relates the total energy of the system, , its wavefunction , a function of particle coordinates (spatial or momentum, spin), and the Hamiltonian operator .
The Hamiltonian for a typical chemical system will be something like:
where and are kinetic energy terms for the electrons and nuclei and , and are potential energy terms for electron-electron, electron-nuclear and nuclear-nuclear interactions.
- and indicate electrons,
- and indicate nuclei with nuclear charge and mass ,
- is the Laplacian