if 2 atoms combined their 4f orbitals, what type of orbitals should form?
I looked for, but could not find, anything on Google that gave an answer to your question. I did find this site that gives some info on how to set up MO bonds. Perhaps it will help you get started.
https://www.chem.fsu.edu/chemlab/chm1046course/motheory.html
To determine the type of orbitals that form when two atoms combine their 4f orbitals, we need to consider the rules of orbital hybridization.
The 4f orbitals belong to the f subshell, which can hold up to 14 electrons in total. The f subshell has a complex shape and is involved in the formation of inner transition elements.
Now, in order to combine the 4f orbitals of two atoms, we need to follow a process called hybridization. Hybridization involves the mixing of atomic orbitals to form new hybrid orbitals with different characteristics and shapes.
However, hybridization typically occurs with the outermost (valence) orbitals of the atoms, not the inner d or f orbitals. The 4f orbitals are not directly involved in bonding between atoms.
That being said, if there was a hypothetical scenario where the 4f orbitals were involved in bonding, they would most likely form hybrid orbitals that resemble the shape and symmetry of the original 4f orbitals. These hybrid orbitals might be designated as 4f-like hybrid orbitals.
It is important to note that this hypothetical scenario of hybridization involving inner (non-valence) orbitals is not commonly observed in chemical bonding. Instead, other types of orbitals (s, p, d) are predominantly involved in bonding between atoms.
In summary, the combination of 4f orbitals is not a common occurrence in chemical bonding. Nonetheless, if it were to happen, it would most likely form hybrid orbitals that resemble the original 4f orbitals.