The theoretical infrared spectrum of kaolinite [Al2Si2O5(OH)(4), triclinic] was computed using ab initio quantum mechanical calculations. Calculations were performed using the Density Functional Theory and the generalized gradient approximation. The low-frequency dielectric tensor of kaolinite was determined as a function of the light frequency using linear response theory. The IR spectrum was then calculated using a model that takes into account the shape and size of kaolinite particles. A remarkable agreement was obtained between theory and experiment, especially on the position of the stretching bands of OH groups. This agreement provides a firm basis for the interpretation of the IR spectrum of kaolinite in terms of structural parameters.
First-principles modeling of the infrared spectrum of kaolinite / Balan, E; Saitta, Am; Mauri, F; Calas, G. - In: AMERICAN MINERALOGIST. - ISSN 0003-004X. - 86:11-12(2001), pp. 1321-1330.
First-principles modeling of the infrared spectrum of kaolinite
Mauri, F;
2001
Abstract
The theoretical infrared spectrum of kaolinite [Al2Si2O5(OH)(4), triclinic] was computed using ab initio quantum mechanical calculations. Calculations were performed using the Density Functional Theory and the generalized gradient approximation. The low-frequency dielectric tensor of kaolinite was determined as a function of the light frequency using linear response theory. The IR spectrum was then calculated using a model that takes into account the shape and size of kaolinite particles. A remarkable agreement was obtained between theory and experiment, especially on the position of the stretching bands of OH groups. This agreement provides a firm basis for the interpretation of the IR spectrum of kaolinite in terms of structural parameters.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.