SEARCH Articles Figures Tables Acid-base concepts frontier orbitals Atomic orbitals modem concepts Basic Concept of Orbital-Dependent Functionals Central atom concepts hybridized orbitals Fragment concepts frontier orbitals Frontier orbital concept Molecular orbital concept Molecular orbitals modem concepts Natural bond orbital concepts Orbit, concept variational principle Orbital Basis Concept Orbital interaction concepts Orbital rearrangement concept Orbital steering concept Orbital symmetry basic concept The concept of molecular orbitals in other systems Use and misuse of the hybrid orbital concept Woodward-Hoffmann orbital symmetry concept