Molecular Orbitals

This program is designed to visualize the wave functions (orbitals) of the hydrogen molecule by superposition of atomic wave functions. This rough approximation allows to get a quick impression how the molecular orbitals develop from atomic orbitals when two atoms are approaching. Atomic wave functions for the different quantum numbers n, l and m can be superimposed symmetric (even) and antisymmetric (odd), resulting in bonding and antibonding molecular states. The wavefunction and its sign is displayed as color-map, which makes it easy to identify the lobes of the orbitals. The program is for free. It has been tested carefully and should work with all current windows versions. However, we can not give any warranty that it will work with your individual computer. With downloading the program you agree that any liability is excluded.

When starting the program, two hydrogen atoms in the 1s state are shown. The distance of the nuclei is large. With the scroll-bar on the right side of the window you can change the distance of the atoms. When approaching to a few atomic units, the atomic wavefunctions are overlapping (1 atomic unit = 0.5292 Angstrom). The bond-length of the hydrogen atom in the ground state is 0.74 Angstrom = 1.4 atomic units.

On the left side, other states can be chosen by their atomic quantum numbers. Each atomic state has two corresponding molecular states belonging to a symmetric (even) and an antisymmetric (odd) combination of the atomic orbitals. The names of the atomic orbitals and of the resulting molecular orbital is shown on the left side. There is also displayed the currently chosen distance of the nuclei. Zoom and colour density can be adjusted with sliders. In the lower left corner can be chosen, if the wavefunction itself or the density should be plotted. In case of density, the colours still indicate the sign (phase) of the wavefunction. The size of the window can be chosen as needed. Large windows need longer to refresh the drawing. Colors of orbitals and background can be chosen using the menu. The currently displayed picture can be saved as an jpeg or bmp image or can be printed directly. Note that the resolution of the saved image is that of the currently shown window.