Enriching quantum chemistry with Mathcad

discover that there is more to learn about science than just the theories, fads, and pmblem-solving methods usually presented in the classroom and tex...
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Chemical €ducation: Software Abstracts for Volume ID, Number 2 Bonding Theoryfrhe WernerJergensen Controversy David M. Whisnant

Wofford College

Spartanburg, SC 29303-3663 This two-part simulation introduces students in heginning chemistry courses to the process by which concepts of molecular structure and bonding developed during the 19th century. The aim ofthe simulation is to help students discover that there is more to learn about science than just the theories, fads, and pmblem-solving methods usually presented in the classroom and textbooks. The proeess of sciencehow scientific change occurs and how scientists behave--also can be very interesting. This program, which originally was written for the Apple II ( I ) , has heen extensively revised to NU under Microsoft Windows 3.x using ToolBook 1.5. The new version includes not only a story-line that leads students through nearly 100 years of ideas about chemical bonding, but also a hypermedia database that presents extra information about the theories and the chemists who were involved. Hypermedia offers students many paths in which to move around the simulation and gives them a greater sense of exploration than was possible in the older and more linear version. The new version also is much improved visually. One of its goals is to see the development of bonding theory through the eyes of 19th century chemists; the realistic pictures of many of these chemists create an atmosphere that furthers this goal. The simulation is divided into two parts. The first develops Berzelius's idea of dualism, the radical theory of organic compounds, the breakdown of dualism, and the rise of the concept of valence and tetrahedral carbon. This is done through computer-simulated interviews with Berzelius, Wohler, Dumas, Liebig, Gerhardt, Frankland, and KekulB. Students are asked to formulate structures using each of the theories so that they can better appreciate how the theories worked and why they ultimately failed as new compounds were synthesized. This part is based upon descriptions of the period 1810-1860 given by Ihde (2)and others (3-12). In the second part of the simulation students learn about the chain theory of Blomstrand and Jorgensen and Werner's coordination theom, Thev then are challeueed to compare the two theoncs a i d to defend their choireiased won the conductivitv results of Werner and M~oIntiI 136. I&) and on differences in the prediction of numbers of iso: mers (13a. 13b). The ex~erimentalresults available change during the simulation-ne isomer is not prepared until students have worked throuah the corn~arisunofthe two theories. At any time d u r i g t h i s part,-the students can obtain guidance from Werner and Jorgensen to help them in their choices of interpretation of the data. The simuation includes pop-up questions that help direct student exploration and provide a means by which their level of success can be evaluated. The questions 902

Journal of Chemical Education

Sophus Maos mgensen maws a sLggeslon regaro ng coora naton theor) n Bond ng Theoryfrne Werncr-srgensenControversy posed also encourage students to think about the connections between the simulation and modem chemistry and about the process of science. With respect to the latter, one section of the hypermedia database includes a discussion of Thomas Kuhn's portrayal of scientific revolutions (14). The complete simulation provides a hands-on introduction to the methods of science and the behavior of scientists that is far more realistic than most textbook discussions of the "scientific method". Acknowledgments The author is grateful for the assistance and helpful suggestions of Terry Fekguson. Partial support for this work was provided by the National Science Foundation's Instmmenktion andI,al,onitory Improvement Prngrnm through grant li USE-9151873.The author alw thanks the BellSouth Foundation for partial support.

Enriching Quantum Chemistry with Mathcad Frank Rioux Saint John's University Coilegeville, MN 56321 Mathcad is a comprehensive, inexpensive program for doing numeric and symbolic mathematics on a computer. It runs under Windows and has an appealing, userinterface. Mathcad has a wide varietv of friendly - .ma~hical . . appllcatlons in the undergraduaw chemistry curriculum, but is rspeciallv useful in the mathemirticallv intensive courses &aditiohally found in the physical chkmistry sequence. (15, 16, 17, 18) As the title suggests this module presents applications of Mathcad in the area of quantum chemistry. Students generally fmd quantum chemistry to be highly mathematical, quite difficult, and very ahstrad. They are right on all counts. However the subject is also extremely important today, even at the undergraduate level. There is, therefore, a need for relatively simple computer exercises that bridge the gap between the formalism of quantum theory and its various computational methods (19).All of the Mathcad documents presented here attempt to do this in one way or another. Some exercises involve relatively

"Enriching Quantum Chemistry with Mathcad" is designed to be used in physical chemistry or in a separate course on quantum chemistry. I t is an electmnic textbook of quantum chemistry in which the equations and graphs are "live". Changing a parameter or equation causes all calculations to be redone. The new results are displayed either as a table of numbers or a s a graph or both. The opportunities for exploration and enhanced understanding of the meaning of quantum chemical equations are nearly infinite. This is a preview of what the textbook of the future might look like.

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Equations, tables of data, and a graph from a Mathcad document on Planck's radiation equation. From "Enriching Quantum Chemistry with Mathcad.

Hardware and Software Requirements Series D of JCE: Software reanires Microsoft Windows version 3.0 or later and associaGd hardware as defined by Microsofl. We recommend an IBM-PCIAT. PSD. or cornoatible computer with a 80386 or higher &ocessor, a kinimum of 4 MB of memow. a hard disk. one flovvv disk drive to install the software,-a mouse, and a winhbws-cornpatible graphics card, such a s an IBM VGA or a Super VGA adapter with a compatible color monitor. DOS version 5.0 or later is highly recommended. In addition to the hardware and s o h a r e recommended above, Enriching Quantum Chemistry with Mathcad requires Mathcad version 3.1 or greater (not supplied). I t also benefits greatly from the presence of a math coprocessor, which is highly recommended. Literature - Cied I. Whimant, D. M. J C h . Educ.:S&mre 1989,IIA. No. 1. 2. Ihde, A. 3. Thefiwlopment ofModDm Chemistry; Dwer: New Ymk, 1964. 3.Maekle.H.J.Chem Edue. 1954,31,618. 4. Kauffman, G.B. J ChamEdue 197a,49,su. 5 . Peterson, J. Z Phys. Chem. 1892,IO. 580. 6. Mmre, E J. A History of Chemistry: McCrccwccHill:NewYork, 1939. 7.Leicaster, H. M. T h o H i s f a ~Bockground l dChoml8try; Wiley:New York, 1956. 8. Kndlay.A.AHundrpdEars ofChemishy, 3rd d . ; Dnekworth: Landon, 1966. 9. Pdmer, W. G. A History offheConcept of Vakney; Cambridge University Cambridge, !andanrl % S. .. . , i. 10Rupsd1, C.A. The HistaryofVoknev, LeicesterUniversity: Leieater,England, 1911. 11. Benfey, 0. T Clm~ssiesin (he History of Chemical Combimtion; Dover: New Yorh, 1963. 12. Renfey, 0. T F m m W o l Porn to Sbuetvml Fomulm; Houghtrm-MiRlin: B o b , 1-A 13. K a u h , G. B., Ed. Classics in Cmnlinotion Chrmiafry;Dover: New YmX,1986; V0l. 1. Translations of articles including (a1 Werner, A.Z A"w. C h . 1m,3. ~

elementarv vroblem solvine, while others, for example, illustrate the basics of moi&dar orbitaltheory a i d the variational method. An example of how Mathcad handles data, text, mathematics, and &aphics in a single live document is shown in the accompanying figure. This module includes Mathcad documents in the following areas: Routine problem solving and units management Applications of integral and differential calculus in quantum mechanical calculations Linear, nonlinear, and polynomial regreasion analysis Numerical solutions for SchrCdinger's equation A maleeular orbital calculation on the hydrogen molecule ion The variational method

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267; (bl Werner A.; Mio1sti.A. Z.Phpik. Chem. 1888,12,35: (c) Werner. A ; Mio1ati.A.Z. Phyrik. Chem. 1894,14,506. 5. The Struetun of Scimtifre Rouolutions, 2nd d.:University of Chicago:

14. Kuhn,

About This lssue How to Use These Programs "Bonding Theory~TheWerner-Jergensen Controversy" is designed to be used in general chemistry, or in any course where descriptive inorganic chemistry is included. I t requires some background in bonding thwry (ionicversus covalent bonding) but does not require that a student have any background in the structures of coordination compounds. Indeed structural coordination chemistry can be developed primarily by the program, minimizing the time that needs to be spent lecturing on the subject. This software would also fit very well in a course on history of chemistry, to illustrate the development of bonding theories and structural chemistry of coordination compounds, or to illustrate how new scientific ideas supplant the old.

To Order This lssue Journal of Chemirol Kducolion: Soflware (oRen called JCE: Softwarel is a oublication ofthe Journal e an Order Form card of Chemical ducati ion. ~ h k r is inserted in this issue. If this card is not available, contad: JCE: Software, Department of Chemistry, University of Wisconsin-Madison, 1101 University Avenue, Madison, WI 53706-1396; 6081262-5153 (voice); 6081262-0381 (FAX); e-mail: jcesoftG3macc.wisc.edu.

Volume 70 Number 11 November 1993

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