Substantial part of the recent progress in deeper understanding the properties of zeolites, their active sites, defects, interactions with guest species, as well as their sorption and catalytic behavior was done with coherent contributions from experimental studies and computational modeling based on quantum chemical methods. The significant progress of computational resources allowed simulations to approach complexity of real systems. 

The first topic is connected with the interpretation of experimental spectral features and acidity of OH groups in zeolites as well as the interplay between silanols and bridging hydroxyls. An advantage of our modeling is that one has consistent information about the spectral and structural features of each individual OH group. In this way we derived correlations of the calculated ¹H NMR chemical shifts and stretching O-H vibrational frequencies with the formed H-bonds [1]. The calculated acidity of the hydroxyl groups is found to be in the range of super acids in the gas phase, but it does not correlate with the NMR or IR spectral features [2].

The second topic is related to location of germanium centers in germanosilicate zeolite and influence of the template on it based on the relative stability of the structures. The results suggested that in the studied zeolite germanium centers tend to cluster in part of the double four rings, while other double four rings are composed only by silicon T atoms for both SCM-14 [3] and SCM-15 [4] structures. The simulations also clarified that the influence of the OSDA on the germanium distribution is strong and for SCM-15 the presence of OSDA even alters the stability order of the structures with different germanium distribution [5]. The research is supported by Bulgarian Science Fund, contract № КП-06-ДВ-2/16.12.2024.