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QCMP013. LAOCN3: Computer Simulation of Complex NMR
Spectra
by A. A. Bothner-By and S. Castellano, Mellon
Institute, Pittsburgh, Pennsylvania 15213
Modified by Matthew Clark and Joseph S.
Thrasher, Department of Chemistry, The
University of Alabama, University, Alabama
35486
This system represents quite a bit more than a conversion of QCPE 111 to the IBM-PC, although that is certainly part of it. The authors have written a separate system in BASICA which assists the user in preparing input for LAOCN3 and then actually calling it. When LAOCN3 is finished, this system permits the user to graphically display his results on the IBM-PC monitor and to actually focus on a specific segment of the spectrum by using a rescaling procedure contained in the system. LAOCN3 itself is the third revised version of a program for the analysis of high-resolution NMR spectra. The program has two capabilities: (1) From an arbitrarily chosen set of chemical shifts and coupling constants for a system of two to seven spin- nuclei, it can cause the computer to generate a table of frequencies and intensities of the lines expected in the nuclear magnetic resonance spectrum; and (2) If a spectrum thus calculated bears a recognizable resemblance to an observed spectrum, the program can cause the computer to perform an iterative calculation by means of which the calculated frequencies of assigned lines are brought as close as possible (by the least-squares criterion) to the corresponding observed lines. The chemical shifts and coupling constants which yield this best fit are then printed out, together with information about the expected errors in them and tables of observed and calculated line frequencies, calculated intensities, and errors in fitting the frequencies of observed lines. NOTE:To use this system you should have a color monitor as well as the BASICA interpreter which is part of MS DOS 2.0. To print the spectra which are produced, you need the GRAPHICS screendump utility. FORTRAN 77 (Microsoft FORTRAN) and BASICA Lines of Code: 1400 |