Near Infrared Spectroscopy

Some of the concepts that make a near infrared spectrum understandable are reviewed. The origin of vibrational anharmonicity which determines the occurrence and the spectral properties (frequency, intensity) is discussed. The importance of the effects of the resonances which increase with increasing excitation are mentioned. Some of the characteristics of high energy overtone/combination spectra are considered in relation to local mode effects. The location of some particular group frequencies is provided.