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Geometry Optimization Lab Activity

Geometry Optimization Main Page

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• Scientists use three measurements to define a molecule's geometry:
1. Bond Angles (measured in degrees)
2. Bond Lengths (measured in angstroms)
3. Dihedral Angles (measured in degrees)
• The optimal geometry of a molecule is the geometry that corresponds to the lowest single point energy calculation of the molecule.
• Potential Energy Surfaces (PES) are mathematical representations of various geometries and their corresponding single point energies.
• PES can be used to find quick estimates of the optimal molecular geometry by locating the minimum point on the graph.
• Computer programs that calculate optimal molecular geometries use three types of calculations:
• In order to run a geometry optimization on the computer, you must enter an initial set of cartesian coordinates and a basis set. The Shodor Education Foundation, Inc.