where E(I*) is the difference between a ground and the first excited state energy. The dissociation energy, D.", from potential minimum is approximated as = D,"
D."
+ 112 w",
-
(2)
where the force constant, o," = 215 em-', is given as G(22
-
0) - G(22
-
1)
a,"
(3)
The dissociation energy for the excited state is calculated, using
D . '
= E* - v.
+ 1/2we0
(4)
where u. is determined by observed transition frequency u,
The program is written in Basic and runs on an Apple IIe computer with 64K memory. I t consists of 293 lines including 41 remark statements. Plots of Birge-Sponer and Morse potential are drawn on the screen. Plots on paper can be reproduced by using an Okidata 92 A printer with Grappler interface. Documentation. available on disk or Daner. . . . includes listing and explanation of program lines with a samole cxerution: all choices are automaticalls- disolaved . . when the terminal is turned on. Copies of the program are available from Project SERAPHIM on 5'/4-in. disk.
+
screen at the cursor. The program then returns to the cursor mode. Attempts to enter invalid input are ignored by the program. Mistakes are erased by positioning the cursor to the lower left of the symbol to he erased and then pressing the R (rubout) key. Super- and subscripts, a t the top and bottom edges of the screen respectively, are erased when the position below or above is erased. The ESCAPE key branches the user to the main menu. Here the user can dump the picture normal or double size to the minter. save the nicture to disk. load a nreviouslv construcred picture. erase thewholescrren,or quit the program. The d u r n ~ - ~ i u t usubroutine re uses an Oraner .Micro C~ r a u pler printe; interface card connected to a-C. Itoh 8 5 1 0 ~ printer. The screen dump subroutines are each one line long and can be easily changed to match another intelligent printer card. For those users without an intelligent printer card, the disk also contains a n Applesoft machine language program that allows the user to get a double-size print-out using an Epson MX80 printer with Graphtrax. For other printerinterface combinations. the user will have to make hisher own arrangements for &ntinga stored picture. I have sui.cesslull\~used the Anolewriter Tonlkit and Print S h o from ~ .. Beagle roth hers. Directions for using the program are stored separately as Directions-40. Running this program gives the user a choice of a 40-column print-out or an on-screen presentation. The ~
Patrlck Flash
Kent State University-Ashtabula Campus Ashtabula. OH 44004 Some of this column's readers may be familiar with the program NUDRAW devised by Victor Bendall of Eastern Kentucky University and available through Project SERAPHIM. (Editor's Note: an updated version, CHEMUTIL-2, isnow available from SERAPHIM.) The program allows you to draw chemical formulas, with correct super- and subscript:, on the Apple 11's page-tw graphics screen as part of a Rasic uroeram. NIJDHAW takes some time eettine used to because yo; have to look up various five-digicdeciial codes for each chemical erouD such as CHI. CH?. etc.. that vou want on the screen. he NU DRAW";^^^
