Tutorial

The following instructions will build the formaldehyde molecule, optimize its geometry, and display the results:

1. Log in to the WebMO Demo Server as Username="guest" and Password="guest" (no quotes)
2. In the WebMO Job Manager page, click "New Job"
3. In the Build Molecule page, in the WebMO Editor applet:
   • Note the status line ("Build Mode - C ..."); click in the middle of the applet to insert a carbon atom
   • In the menu, choose Build: O to make oxygen active; note the status line
   • Click on the C atom, drag, and let up the mouse button to insert a bond to an oxygen atom
   • Drag between C and O again to change the single bond to a double bond
   • In the menu, choose Clean-Up: Comprehensive; note that hydrogens are added, bond lengths are idealized, and bond angles are idealized (WebMO knows organic chemistry!)
4. In the bottom right corner of the Build Molecule page, click the Continue arrow
5. In the Choose Computational Engine page, click Mopac, and then click the Continue arrow
6. In the Configure Mopac Job Options page:
   • Select Calculation: Geometry Optimization
   • Click the Continue arrow to submit your job; note that your job appears in the WebMO Job Manager page
7. In the WebMO Job Manager page, click "Refresh" to update the page; note that the job Status is Complete
8. Click the job title "CH2O" to arrive at the View Results page; scroll down to look at your Calculated Quantities; in particular:
   • Note the computed Symmetry (C2V), Heat of Formation (-34.08 kcal/mol), and Dipole Moment (2.16 Debye)
   • Note the computed C=O bond order (1.98) and C-H bond order (0.93)
   • Click the Partial Charge View icon (magnifying glass)
   • In the WebMO Viewer applet, click O, shift-click C, and shift-click H; look at the status line to view the computed O-C-H bond angle
   • To the left of the WebMO Viewer applet, click the Raw Output link to see what Mopac actually calculated

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