Click ok and then ok again to close the setup dialog

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Unformatted text preview: ypton, built into the program with approximations to make it possible (called the Hartree-Fock approximation). In the dialog box that pops up, click the “small” radial button (3-21G). Click the “options” button, and be sure “RHF” is clicked, and charge is set to 0. The other default values should be fine (convergence limit 1e-008, iteration limit 50, accelerate convergence chosen, gradient and MP2 not chosen). Click on “polarizabilities” and be sure “do not calculate” is clicked. Click on “Configuration Interaction” and be sure “none” is highlighted. Click “OK.” Click on “Advanced Options.” In the dialog box, be sure “five d orbitals” is chosen. For “MO initial guess” choose “core Hamiltonian.” Choose “regular” for integral format, and select “direct SCF calculation.” “Cutoff” should be 1e-010 and buffer size 32000. Click “OK.” Click “additional basis sets” and be sure “none” is selected. Click “OK” and then “OK” again to close the setup dialog box. Go to “Compute” and click on “Single Point.” The system will begin calculating the electronic configuration for Krypton. You know the calculation is proceeding if “Cancel” is the only menu option available; it will be the only option that is NOT available once the calculations are complete. Let this calculation run to completion. Once the computation is complete, go to “Compute” and choose “Orbitals.” This will open a dialog box. The shape of the orbitals has already been computed; this is just how you can bring out the properties of these orbitals. Click and drag the dialog box so you can see the Krypton atom in the main HyperChem window. You will notice two radial buttons called “LUMO+” and “HOMO-.” LUMO stands for “lowest unoccupied molecular orbital;” these are orbitals that have no electrons in them (lowest means lowest energy), while HOMO stands for “Highest Occupied Molecular Orbital.” Be sure “3D isosurface” is chosen and “orbital squared” is also chosen. For the occupied orbitals, put in the appropriate value to complete the table for part III in the results section. Be sure “HOMO-” is selected and put the appropriate number in the box below. Then click on “plot.” You need to close the dialog box by clicking “OK” if you want to Dakota State University Page 99 of 232 Experiment 7: Quantum Mechanics General Chemistry I and II Lab Manual rotate the orbital; just re-open it as previously if you choose to do so. Repeat this for the unoccupied orbitals, being sure “LUMO+” is chosen. Notice that these orbitals do exist, even though they are not utilized. Finally, arrange the shell/subshells from lowest to highest energy from both the occupied and unoccupied tables. How does this order compare with the order of filling using the Aufbau process? Results Occupied orbitals: HOMO17 16 15, 14, 13 12 11, 10, 9 8, 7, 6, 5, 4 3 2, 1, 0 Shell/subshell 1s 2s 2p 3s 3p 3d 4s 4p Energy Shape* *Notice that inner shells may not appear correct because of approximations and scale. Unoccupied orbi...
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This note was uploaded on 09/18/2012 for the course CHEMISTRY 1010 taught by Professor Kumar during the Fall '11 term at WPI.

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