[honeycomb79]

I am doing an exercise about the MO diagram for SF4. For sulfur, the 2s orbital and one of the P orbitals have the A1 Mulliken symbol, and 2 of my SALCs for F have the A1 Mulliken symbol as well. I know that I will get one bonding and one antibonding MO from their interaction, but would the other two A1 MOs be nonbonding, or would one be bonding and one antibonding?

If I make it so out of my four A1 MOs, two are bonding and two are antibonding, I get a bond order of 4, which makes sense for SF4. So, is this confirmation that this is how I should be treating the MOs?

Thanks xx 

[Orcio_87]

If I make it so out of my four A1 MOs, two are bonding and two are antibonding, I get a bond order of 4, which makes sense for SF₄.

How it is possible? Look here: https://techiescientist.com/sf4-lewis-structure/

If third A1 MO is anti-bonding this will make the bond order = 3 instead.