Scale	Value	Source	Method
pauling	2.580	Database	The original and most widely used scale, based on bond dissociation energies. Fl...
allen	15.310	Database	Based on the average energy of valence electrons in free atoms. Provides configu...
ghosh	0.236	Database	Theoretical scale based on absolute electronegativity using DFT calculations.
mulliken χ = (IE + EA) / 6.30	1.974	Calculated	Average of ionization energy and electron affinity, normalized to Pauling scale.
allred rochow χ = 0.359 × (Z_eff / r²) + 0.744	2.291	Calculated	Based on effective nuclear charge and covalent radius. Relates to electrostatic ...
sanderson χ = 0.31 × (electron density)^(1/3)	0.485	Calculated	Based on electron density of atoms. Uses concept of stability ratio for equaliza...
gordy χ = 0.31 × (Z_eff / r) + 0.50	1.902	Calculated	Linear relationship between electronegativity, effective charge, and radius.
cottrell sutton χ = 0.35 × (Z_eff / r) + 0.60	2.183	Calculated	Similar to Gordy scale with adjusted empirical constants for better correlation.
nagle χ = (Z_eff^1.5) / (5r)	1.972	Calculated	Density functional approximation emphasizing the role of effective nuclear charg...
martynov batsanov χ = 0.47 × (Z_eff / r) + 0.62	2.746	Calculated	Refinement of charge-to-distance ratio approach with optimized empirical paramet...
li xue χ = (IE₁ + IE₂ + ... + IEₙ) / (5.5n)	4.155	Calculated	Quantum mechanical approach using average of multiple ionization energies of val...