A CONTINUOUS ELECTRON DENSITY APPROACH IN RIETVELD ANALYSIS FOR STRUCTURE INVESTIGATIONS OF THE MESOPOROUS SILICATE MATERIALS, L.A. Solovyov, S.D. Kirik, A.N. Shmakov, V.N. Romannikov, pp. 110-115

A procedure of the structure factor simulation from a continuous electron density representation in combination with the full-profile structure refinement (Rietveld technique) was developed and applied to structural characterization of pure siliceous mesoporous mesophase materials C16SiO2-MMM of the MCM-41 type. An analytical function was exploited to simulate the continuous electron density. The function arguments were used as refinable structure parameters. The technique allows both the least-squares refinement of structural parameters using the fullprofile fitting and the E-map calculations providing additional information on the structure details. Determined pore sizes were in good agreement with those obtained by independent absorption-based method. The pore shape was found to be close to hexagonal geometry.