  The C-H vibrational bands become more and more important in the structural
determination of biological molecules with the development of CARS microscopy
and 2DIR spectroscopy. Due to the congested pattern, near degeneracy, and
strong anharmonicity of the C-H stretch vibrations, assignment of the C-H
vibrational bands are often misleading. Anharmonic vibrational spectra
calculation with multidimensional potential energy surface interprets the C-H
vibrational spectra more accurately. In this article we have presented the
importance of multidimensional potential energy surface in anharmonic
vibrational spectra calculation and discuss the unexpected red shift of C-H
vibrational band of Methyl benzoate.
