ERIC Number: EJ1028503
Record Type: Journal
Publication Date: 2013-Nov
Abstractor: As Provided
Reference Count: N/A
Exploring the Nature of the H[subscript 2] Bond. 1. Using Spreadsheet Calculations to Examine the Valence Bond and Molecular Orbital Methods
Halpern, Arthur M.; Glendening, Eric D.
Journal of Chemical Education, v90 n11 p1452-1458 Nov 2013
A three-part project for students in physical chemistry, computational chemistry, or independent study is described in which they explore applications of valence bond (VB) and molecular orbital-configuration interaction (MO-CI) treatments of H[subscript 2]. Using a scientific spreadsheet, students construct potential-energy (PE) curves for several states of H[subscript 2] from the kinetic and potential energies, calculated from closed-form analytical expressions of the ten unique integrals arising from the Born-Oppenheimer Hamiltonian. For this project students use hydrogen 1s basis functions that include a screening parameter. From the calculated PE curves, they find the dissociation energy, D[subscript e], and equilibrium internuclear distance, R[subscript e]. In part I students use the Heitler-London (VB) form of the wave function to obtain the PE curves. In part II they optimize the value of the screening parameter to improve the results, and in part III they explore the treatment of H[subscript 2], using both the simple MO wave function and the application of CI, with and without screening parameter optimization, to obtain the PE curves. Students compare their D[subscript e] and R[subscript e] results with the experimental values. A set of questions, exercises, and a sample spreadsheet are provided as Supporting Information.
Descriptors: Science Instruction, College Science, Undergraduate Study, Spreadsheets, Computation, Molecular Structure, Chemistry, Energy, Kinetics, Educational Technology, Teaching Methods
Division of Chemical Education, Inc and ACS Publications Division of the American Chemical Society. 1155 Sixteenth Street NW, Washington, DC 20036. Tel: 800-227-5558; Tel: 202-872-4600; e-mail: firstname.lastname@example.org; Web site: http://pubs.acs.org/jchemeduc
Publication Type: Journal Articles; Reports - Descriptive; Tests/Questionnaires
Education Level: Higher Education; Postsecondary Education
Authoring Institution: N/A