Intro WebMO 2

(4/9/20, bes)

The following activities is a modification of this...

Exercise 2 - Study of the Molecular Orbitals in Ethene, CH₂CH₂

Note: this calculation is a 2-step process:

1) Optimize Geometry, then,

2) Calculate Molecular Orbitals.

- Click “New Job”, then “Create New Job”. The Build Molecule window opens,

- Build C2H2 using the knowledge gained from the previous WebMO activity.

To build a C-C, with a single carbon on the workspace, click-hold-drag to one side and release. You should now have C-C. Click-hold-drag from the center of one C atom to the center of the other C atom to form the double bond.

- Choose Clean-Up > Comprehensive – Mechanics. You should now have ethene.

- Click the blue “continue” arrow in the lower right side of the Build Molecule window. If you receive the following message when stepping forward, select "cancel" and then symmetrize the molecule by clicking on the red icon (10th item in the left toolbar).

- Setup the job as shown below and submit:

- Once the job is complete, click on the hyperlinked name to open the “View Job” window.

- Click the "New Job Using This Geometry" button at the bottom of the window, then click the blue “continue” arrow,

- Setup the job as shown below and submit:

- Once the job is complete, click on the hyperlinked name to open the “View Job” window.

- Scroll down to the Molecular Orbitals table. Using the energy values and occupancy as your judge, identify the HOMO and LUMO. View these orbitals by click on the magnifying glass icon. The orbitals can be rotated by clicking and dragging in the viewer window.