AO	atomic orbital
C-DFT	Conceptual Density Functional Theory
DFT	Density Functional Theory
EA	electron affinity
EF	electric field
IP	ionization potential
KS	Kohn–Sham
LRF	Linear Response Function
MO	molecular orbital
NTO	Natural Transition Orbital
QTAIM	Quantum Theory of Atoms-in-Molecules
RS	Rayleigh–Schrödinger
TDA	Tamm–Dancoff Approximation