source of randomness (random number generator) selected, etc., so in case of such
structures there is still much to be done in the future, when significantly faster
computers will be available.
A separate group of computational problems, extremely important for catalysis,
concerns the method of describing the surface or space inside the catalytically
active mesoporous materials (zeolites, MOFs) or clusters and the catalytic properties of these materials. This is a very complex issue, worth a separate discussion
in itself, hence far beyond the scope of this chapter. It is worth mentioning, however, that also here there are a number of different approaches related to surface
simulation, catalytically active sites, thermodynamics, and kinetics of catalytic
reactions, etc., similar to those described above. These approaches are based on
standard ab initio methods, hybrid methods combining the accuracy of ab initio
methods with the speed of classical methods based on classic interparticle potentials
(e.g., ONIOM [139]), but also dynamical or statistical (both, classical and ab initio)
Fig. 1.4 SrTiO 3 unit cell (a); 3 Â 3Â3 extended unit cell (b); 3 Â 3Â3 superstructure with one
(1:28 doping ratio) (c); and three point defects (1:8 doping ratio) in one of the possible, exemplary
configuration (d). The defects are depicted in different color and size for better visibility
1 Computational Methods in Spectroscopy
39
structures there is still much to be done in the future, when significantly faster
computers will be available.
A separate group of computational problems, extremely important for catalysis,
concerns the method of describing the surface or space inside the catalytically
active mesoporous materials (zeolites, MOFs) or clusters and the catalytic properties of these materials. This is a very complex issue, worth a separate discussion
in itself, hence far beyond the scope of this chapter. It is worth mentioning, however, that also here there are a number of different approaches related to surface
simulation, catalytically active sites, thermodynamics, and kinetics of catalytic
reactions, etc., similar to those described above. These approaches are based on
standard ab initio methods, hybrid methods combining the accuracy of ab initio
methods with the speed of classical methods based on classic interparticle potentials
(e.g., ONIOM [139]), but also dynamical or statistical (both, classical and ab initio)
Fig. 1.4 SrTiO 3 unit cell (a); 3 Â 3Â3 extended unit cell (b); 3 Â 3Â3 superstructure with one
(1:28 doping ratio) (c); and three point defects (1:8 doping ratio) in one of the possible, exemplary
configuration (d). The defects are depicted in different color and size for better visibility
1 Computational Methods in Spectroscopy
39