|
497. PAIRS: Program for the Analysis of Infrared Spectra
(VAX Version)
by Sterling Tomellini, Graham M. Smith and Hugh B. Woodruff, Merck Sharp & Dohme Research Laboratories, Rahway, New Jersey 07065 PAIRS has undergone major changes and advancements since first being released to the public through QCPE (as QCPE 426) in 1981. Noteworthy advancements include (1) modification of the program to allow "vapor" as a sample state and generation of interpretation rules for vapor-phase species and (2) the development of a version of PAIRS capable of allowing the user to determine quickly how the expectation value for a given functionality has been determined. This version of PAIRS for the VAX contains these changes. Other relatively minor changes were necessary to make PAIRS compatible with the VAX 11/780. These changes are basically user transparent, thus minimizing the inconvenience caused on switching to the new version. All capabilities of the IBM version have been duplicated for the VAX version, with the exception that a final report is not automatically printed. PAIRS was designed to interpret IR spectra of condensed-phase species (liquids and solids); but it was realized that the usefulness of the program could be further enhanced if IR spectra of vapor-phase species could also be interpreted. Major changes were made to both the interpreter and the rule compiler to allow "vapor" to be included as a sample state. Interpretation rules were developed based on Welti's book Infrared Vapour Spectra (Heyden: New York, 1970) for such functionalities as alcohols, phenols, amines, amides, acids, esters and ketones. The new rules were incorporated in such a way as to ensure the uncompromised nature of the previously developed (and extensively tested) condensed-phase rules. These rules are designed to allow the spectra of intermediate molecular weight compounds taken at moderate resolutions to be interpreted. This added capability should be of particular interest to those scientists employing techniques such as GC/FTIR, off-gas and head space analysis. Furthermore, the program changes now make it possible for other users to develop interpretation rules for vapor-phase species to meet their particular needs. The intent when developing PAIRS was to create a program which would give a numerical indication of the presence or absence of a given functionality based on spectral information and a set of interpretation rules. Every effort was made to make the interpretation rules accessible and understandable, thus the rules were written in the English-like language CONCISE. Manually tracing the decision-making process can, however, be a difficult and tedious task which essentially limits the user to relying on the numerical indications presented without further elaboration. In order to make PAIRS more responsive to the needs of the practicing research scientist, the program has been modified to allow the decision-making process to be traced quickly in an automated manner. Allowing the decision-making process for a given functionality or all functionalities advances the program from being primarily an interpretation tool to being an information resource as well. This added capability should also greatly aid in the development of interpretation rules by allowing the quick evaluation of newly created rules. FORTRAN 77 (VAX) Lines of Code: 21,000 |