Hello Everyone,
I am new to ase and also to quantum chemistry and DFT toolsets and therefore i am seeking some help in the problem that i have.
I am trying to get the thermodynamic and kinetic parameters for the corrosion (oxidation) of carbon due to water. For simplicity lets say the reaction goes like this:
C(s) + H2O ↔ (C-OH)ads + H+ + e-
(C-OH)ads ↔ (CO)ads + H+ + e-
(C-OH)ads + H2O → C(s) + CO2(g) + 3H+ + 3e-
How can i do that using ase and quantum espresso?
The model is as follows: 6x6 super cell of Hex graphene (optimized): There are several such layers with a vacuum of 21 Angstroms in between (Are the multiple layers necessary if the focus is the surface oxide formation?). A water molecule (optimized) is then needs to be placed 3.31 Angstroms above one of the carbon atoms. How can i do the optimization and place the molecule right where i need it?
Creating supercell and creating water molecule i was able to do. But how do i do the optimization and then place them in the right place? Also how can i consider all the three adsorption reaction? I saw somewhere that NEB can be used. Since i am not familiar with the syntaxes, i am struggling a bit.
Furthermore how can i get vibrational frequencies and finally the thermodynamic and kinetic parameters for the above mentioned reactions?
I would be glad if someone could explain me with an example (preferably similar problem as mine). I thank you in advance.