Hard Lewis acid (generic) Pearson hard Lewis acid (generic)   Special class of generic used to represent "generic chemical reactivity behaviour" rather than structure. Wikipedia Page: Hard Lewis acid (generic) is defined with respect to the entities below: The entities below are defined with respect to: Hard Lewis acid (generic) Aluminium chloride Aluminium chloride dimer Aluminium hydride Aluminium ion Arsenic(III) ion Beryllium ion Boron trifluoride Calcium ion Carbon dioxide Cerium(III) ion Chromium(III) ion Chromium(VI) ion Cobalt(III) ion Gallium(III) ion Hydrogen bond complex (generic) Indium(III) Ion Iron(III) ion Lanthanum(III) Ion Magnesium ion Manganese(II) ion Molybdenum(III) ion Nitronium ion Potassium ion Proton Scandium(III) ion Sodium ion Sulfur trioxide Tin(IV) ion Titanium(IV) ion Uranium(IV) ion Zirconium ion chemical compound molecule metal molecular science reaction mechanism ionic material acid base geometry reactivity synthesis science knowledge chemistry Lewis