Will be discussed in more detail in a future tutorial. Scaler uses a coefficient matrix to map descriptor-space to parameter space and Since we have not explicitly specified a scaler the default The next thing we want to specify are some parameters for the scaler.
frozen_adsorbate - Do not include any corrections. zero_point_adsorbate - Only includes zero-point energies (assumes. Model and assume all but three degrees of freedom are vibrational, twoĬome from hindered translations, and one comes from a hindered rotation hindered_adsorbate - Use a hindered translator and hindered rotor. 
harmonic_adsorbate - Use the harmonic approximation and assume allĭegrees of freedom are vibrational (implemented viaĪse.thermochemistry.HarmonicThermo and assumes that frequencies are. Similarly, adsorbate thermochemistry can be approximated by: frozen_gas - Do not include any corrections. zero_point_gas - Only includes zero-point energies and neglectsĮntropy (assumes that frequencies are provided). frozen_fixed_entropy_gas - Same as fixed_entropy_gas except. Gas entropy is provided in _entropy_dict (if not fixed_entropy_gas - Includes zero-point energy and a staticĮntropy correction (assumes that frequencies are provided and that. shomate_gas - Uses Shomate equation (assumes that Shomate. ideal_gas - Ideal gas approximation (assumes that atoms are inĪse.structure.molecule and that arguments forĪse.thermochemistry.IdealGasThermo are specified inĬ_gas_params and that frequencies are provided). ForĮxample, gas-phase thermochemistry can be approximated by: There are a number of other approximations built into the model. Gas_thermo_mode = "shomate_gas" adsorbate_thermo_mode = "frozen_adsorbate" Next, we need to tell the model which surfaces we are interested in. “ H2O_g -> H2O_g” (in the case of adding H2O gas) to “ rxn_expressions”. Reaction network as an atomic reference, you may need to add a dummy reaction like 
If you’d like CatMAP to use a gas species that does not appear in your However, it can only use gas species present in your reaction
In your input file to generate a complete set of reference energies for every element One important thing to note is that uses some subset of gas phase energies present Transition-states, gasses, and surface sites in the model. Parsed automatically in order to define the adsorbates, This means that all intermediates will beĪdsorbed at a site designated as “ s”. We have only included “ *” and “ *_s” sites since this is a single-site Imagined, but these elementary steps capture the key features. More complex models for CO oxidation could be The oxygen molecule, and the final is an activated associativeĭesorption of CO2. The second includes an activated dissociative chemisorption of The first expression includes CO adsorption without any activationīarrier. Surface_name site_name species_name formation_energy bulk_structure frequencies other_parameters reference None gas CO2 2.45 None "Angew.
0 kommentar(er)
