Adsorption of ethylene, benzene, and ethylbenzene over faujasite zeolites investigated by the ONIOM method

Structure and adsorption of a basic probe molecule on H-ZSM-5 nanostructured zeolite: An embedded ONIOM study

“…Furthermore, they often introduce an unrealistic perfect symmetry into the model. Hybrid methods, such as the embedded cluster or combined quantum mechanics/molecular mechanics (QM/MM) methods [23][24][25][26][27][28][29][30][31], as well as the more general ONIOM ('Our-own-N-layer integrated molecular orbital + molecular mechanics') method [32][33][34][35][36][37][38][39][40][41][42] provide a cost effective computational strategy for including the effects of the zeolite framework.…”

Adsorption equilibria of hydrocarbons in the structure of the reforming catalyst: Molecular modeling

“…There are forcefields which describe the behavior of a small atom group with a high accuracy, but when a larger group of atoms is to be described, accuracy will suffer from limitation. The use of empirical data to describe the state of the entire group of molecules is of great advantage in that this reduces remarkably the demand for computational capacity compared to the use of ab initio [7,8]. Owing to this advantage, simulations of much larger models have become feasible.…”

“…Our computations were carried out with the UFF method recommended by the software producer. The UFF had been tested with similar systems containing all the atoms of which the models used in the present study were built [7][8][9]. The comparison of calculated and experimental results raises problems because of the properties of the model that was used for the needs of our study.…”

New Insights into the Role of Amines in the Synthesis of Molecular Sieves in Ionic Liquids

“…This ONIOM2 method has been proven to be an accurate and practical model for exploring the structure, adsorption properties, and reaction mechanisms taking place inside zeolite pores. [43][44][45] All our calculations were performed by using the Gaussian 03 program. [46] To avoid losing the unique structure of the zeolites during structure optimization, only the active site region and the adsorbates were allowed to relax, and the remaining atoms of the cluster model were fixed at their crystallographic locations.…”