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631. FCARTP: A Series of Programs Used to Generate a
Predicted Set of Fundamental Vibrational Frequencies
by William B. Collier, Department of Chemistry, Oral Roberts University, Tulsa, Oklahoma 74171 The method can be summarized as follows. First, a force constant matrix in Cartesian coordinates is generated using a suitable molecular orbital program or other method. Second, from the structure of the molecule a B matrix is calculated and used as input to the FCARTP program. Lastly, FCARTP reads the Cartesian F matrix file and its main input file to obtain all the input data necessary to complete the calculations and produce a set of predicted fundamental vibrational frequencies. Version 1.10 of FCARTP has the capability of: 1. Calculating thefundamentalvibrational frequencies of a molecule or series of molecules or molecular symmetry blocks after scaling (or not scaling) the input Cartesian F matrix according to the method of Pulay, et al., J.A.C.S., 101, 2550 (1979); J. Chem. Phys., 72, 3999 (1980). 2. Adjusting the user-specified scale factors according to the method of nonlinear least squares so that the predicted frequencies of the scaled molecular orbital calculated Cartesian F matrices are minimized with respect to user-entered and weighted experimental vibrational frequencies. 3. Calculating the Cartesian components of and the total intensity of each vibration from user-inputted Cartesian dipole derivatives calculated from the AMPAC molecular orbital program or others. 4. Calculating and printing the scaled and adjusted molecular F matrix in internal coordinates for each molecule entered, the potential energy distribution of each vibrational frequency calculated, the Cartesian vibrational displacements of each vibration calculated, the initial and final adjusted scale factors, and various other spectroscopic quantities and matrices of interest. 5. Performing overlay isotopic calculations and refining scale factors for an isotopic set of vibrational frequencies. 6. Providing instructions for modifying matrices for use in FCARTP. 7. Giving specific line by line instructions for modifying QCPE 506 (AMPAC) and BMAT. FOR of QCPE 342 to provide the user with the necessary Cartesian F matrices and B matrices needed for input into the program. Lines of Code: 5235 FORTRAN 77 (VAX) |