Multivariate Statistical Investigation Of The Effects Of Wave Function Modifications On The Calculated Vibrational Frequencies And Infrared Intensities Of Ch2f2

Factorial design calculations for the vibrational frequencies and infrared intensities of CH2F2 are reported. Vibrational frequencies decrease by about 100 cm-1 compared with results obtained from Hartree-Fock wave functions when the second-order Møller-Plesset perturbation is applied. The inclusion of polarization functions increases the stretching frequencies by about 100 cm-1 and the CH2 and CF2 angular vibrations by about 50 cm-1, whereas it lowers the values of the CH stretching frequencies. CH2F2 calculated frequencies, which are found to have similar factorial design effects, also have optimal calculated results for the same wave function. Principal component projections of theoretical frequency and intensity results are shown to provide accurate graphical representations of how well these results agree with the experimental values. The factorial design models and principal component graphs of CH2F2 are found to be very similar to those of CH3F for the calculated frequencies. However, these results are quite different for the calculated infrared intensities. © 1997 Elsevier Science B.V.39402/03/15197208De Azevedo, A.L.M.S., De Barros Neto, B., Scarminio, I.S., De Oliveira, A.E., Bruns, R.E., Spectrochim Acta A, , in pressDa Silva, J.B.P., Ramos, M.N., Bruns, R.E., Spectrochim. A, , in pressRamos, M.N., Da Silva, J.B.P., Bruns, R.E., Spectrochim. Acta Part B, , submitted for publicationBox, G.E.P., Hunter, W.G., Hunter, J.S., (1978) Statistics for Experimenters, , Wiley, New YorkMardia, K.V., Kent, J.T., Bibby, J.M., (1979) Multivariate Analysis, , Academic Press, London, Chapter 8Suto, E., Ferreira, M.M.C., Bruns, R.E., (1991) J. Comp. Chem., 12, p. 885Sosa, C., Schlegel, H.B., (1987) J. Chem. Phys., 86, p. 6937Fox, G.L., Schlegel, H.B., (1990) J. Chem. Phys., 92, p. 4351Stanton, J.F., Lipscomb, W.N., Magers, D.H., Bartlett, R.J., (1989) J. Chem. Phys., 90, p. 3241Yamaguchi, Y., Frisch, M., Gaw, J.F., Schaefer, H.F., Binkley, S., (1986) J. Chem. Phys., 84, p. 2262Simandirus, E.D., Amos, R.D., Handy, N.C., (1987) Chem. Phys., 114, p. 9Miller, M.D., Jansen, F., Chapman, O.L., Hohk, K.N., (1989) J. Phys. Chem., 93, p. 4495Kondo, S., Nakanaga, T., Saeki, S., (1980) J. Chem. Phys., 73, p. 5409Suto, E., Bruns, R.E., Neto, B.B., (1991) J. Phys. Chem., 95, p. 9716Hehre, W., Radom, L., Schleyer, P.V.R., Pople, J.A., (1986) Ab Initio Molecular Orbital Theory, , Wiley-Interscience, New York, Chapter 4Sharat, M.A., Illman, D.L., Kowalski, B.R., (1986) Chemometrics, , Wiley, New YorkScarminio, I.S., Bruns, R.E., (1986) Trends Anal. Chem., 8, p. 326Frisch, M.J., Trucks, G.W., Head-Gordon, M., Gill, P.M.W., Wong, M.W., Foresman, J.B., Johnson, B.C., Pople, J.A., (1992) Gaussian 92, Revision C, , Gaussian, Inc., Pittsburg, P