I wanna see the feasibility of a chemical reaction $$A \rightarrow B +C$$ where A,B and C are crystal systems. Now I am using VASP in order to calculate the internal energy U, pressure and volume of the system. It is just that I am not very good with thermodynamics. We have $$\Delta H = \Delta U ...

So this question came up in class recently and got me thinking, is there any relationship between the metal d group and the $\Delta_O$ found for some allowed transition in Tanabe-Sugano diagram?

This is actually a follow up of this question The follow-up is not because of the electric instead of magnetic dipole (this is trivial). It is because I'm interested in extra info. Suppose I have a system with $O(h)$ symmetry. The electric dipole allowed transitions from the ground state belong t...

If I have a open shell system (10 alpha electrons and 9 beta electrons) and running TDDFT calculations, is it possible to have a 9a→10b transition? Or does it have to be 9b→10b? Because both exciation won't change the multiplicity of the system, ending with one un paired electrons.