虽然它们的吸附结构是不同的，但是贵金属和碱金属吸附原子在低覆盖度下都能引起类似的电子结构，这表明了吸附表面具有的近二维自由电子近似性质。
Though the adsorption configurations are different , both the noble and alkali adatom adsorptions give rise to similar electronic structures at low coverages , indicating a free-electron-like character of the adsorption surfaces .
近自由电子近似