A thermodynamically consistent, multimodel approach for the prediction of mixture adsorption equilibria from pure-component adsorption isotherms is described. The ideal adsorbed solution (LAS) model is employed at law surface coverage where potential attractive forces tend to govern adsorption behavior. An energetically quasi-homogeneous version of the Langmuir-Freundlich (LF) model is proposed at high coverage, where lateral adsorbate interactions and finite-adsorbent geometric constraints tend to homogenize such attractive forces. The classical LF model is used for intermediate coverage, where both energetic attractive and geometric constraining forces contribute significantly to mixed-gas adsorption behavior. A major benefit of this three-regime modeling method is that physically realistic adsorptive selectivities can be adhered to at both extremes of coverage, a property not generally shared by either the MS or LF models taken singly This three-regime approach yields better multicomponent equilibria predictions than LAS-only modeling approaches for many relatively nonideal absorption systems.