Understanding structures of triatomic molecules from Walsh diagram
In this experiment you will plot the orbital energies as functions of the angle H-X-H of H-O-H and H-Be-H molecules from 90 to 180 degrees. This diagram is known as the Walsh diagram. Using these diagrams to explain why water has the bend structure while ...
In this experiment you will plot the orbital energies as functions of the angle H-X-H of H-O-H and H-Be-H molecules from 90 to 180 degrees. This diagram is known as the Walsh diagram. Using these diagrams to explain why water has the bend structure while BeH2 has the linear structure.
Procedure: Using tools in Avisto. You can download Avisto and its tools from Astonis.
1. Use MolDesign to build 3D structures of water and BeH2 and set the desired value for their angles.
2. Use Mopac GUI Cloud or Pro to run a series of single point energies calculations at each value of the angle from 90 to 180 degrees with 10 degrees interval for both H2O an BeH2. Record the orbital energies and plot all the molecular orbitals.
3. Plot the orbital energies as functions of the angle for H2O and BeH2. Notice how the occupied molecular orbital energies vary as the angle changes from 90 to 180 degrees. Also examine how the orbitals change as the angle changes as well.
Can you then explain why BeH2 is linear while H2O is bend?
