These programs are for calculating the reflectivity as a function of incident angle from a dielectric stack. These N phase Fresnel calculations are used to analyze surface plasmon resonance (SPR) measurements of ultrathin organic films on gold and silver surfaces. Please see the web page: http://corninfo.ps.uci.edu/ for more details of the SPR measurement methodology. This set of pascal files were developed using Borland Turbo Pascal 6.0 for PCs. The files included in this package are: sprangle.pas - program that performs the SPR reflectivity calculation. a_var.pas - unit file for sprangle program a_init.pas - unit file for sprangle program a_calc.pas - unit file for sprangle program mmath.pas - unit file for sprangle program cmath.pas - unit file for sprangle program input.txt - input parameter file for sprangle.pas display.pas - program used to graph the SPR reflectivity curve. The program sprangle.pas needs to be compiled with the various unit files. The input parameters for the Fresnel calculation can be found in input.txt and should be self-explanatory. The output of the sprangle program is a text file 'name.txt' where name is the first line in input.txt. The output file is a list of theta-reflectivity values in x-y format. Please contact us (corn@chem.wisc.edu) if there are any problems. You can use these programs freely; please just reference where they came from. Professor Robert M. Corn Department of Chemistry 1102 Natural Sciences 2 University of California, Irvine Irvine, CA 92697-2025 USA Tel: 1-949-824-1746 Fax: 1-949-824-8571 Email: rcorn@uci.edu Web: corninfo.ps.uci.edu