Scale	Value	Source	Method
pauling	3.440	Database	The original and most widely used scale, based on bond dissociation energies. Fl...
allen	21.360	Database	Based on the average energy of valence electrons in free atoms. Provides configu...
ghosh	0.305	Database	Theoretical scale based on absolute electronegativity using DFT calculations.
mulliken χ = (IE + EA) / 6.30	2.394	Calculated	Average of ionization energy and electron affinity, normalized to Pauling scale.
allred rochow χ = 0.359 × (Z_eff / r²) + 0.744	3.670	Calculated	Based on effective nuclear charge and covalent radius. Relates to electrostatic ...
sanderson χ = 0.31 × (electron density)^(1/3)	0.641	Calculated	Based on electron density of atoms. Uses concept of stability ratio for equaliza...
gordy χ = 0.31 × (Z_eff / r) + 0.50	2.167	Calculated	Linear relationship between electronegativity, effective charge, and radius.
cottrell sutton χ = 0.35 × (Z_eff / r) + 0.60	2.483	Calculated	Similar to Gordy scale with adjusted empirical constants for better correlation.
nagle χ = (Z_eff^1.5) / (5r)	2.027	Calculated	Density functional approximation emphasizing the role of effective nuclear charg...
martynov batsanov χ = 0.47 × (Z_eff / r) + 0.62	3.148	Calculated	Refinement of charge-to-distance ratio approach with optimized empirical paramet...
li xue χ = (IE₁ + IE₂ + ... + IEₙ) / (5.5n)	6.283	Calculated	Quantum mechanical approach using average of multiple ionization energies of val...