Molecular Orbital Viewer

LCAO approximation: ψ = c₁φ₁ + c₂φ₂ — bonding/antibonding MOs from atomic orbitals

Molecule

Orbital

σ1s (bonding)

Display

Blue = +ψ, Red = −ψ
Node planes shown in grey

MO Theory

σ bonding: constructive interference, no node between nuclei.

σ* antibonding: node between nuclei, destabilizing.

Bond order = (bonding − antibonding)/2

O₂ has two half-filled π* → paramagnetic (Hund's rule).