= Vibrational factor in a Langmuir equilibrium constant
{title2=$b_s(T)=z_s(T)\lambda^3e^{\epsilon/(k_BT)}/(k_BT)$}
Equating the site <chemical potential> with that of an internally structureless classical vapour gives $\theta=b_sp/(1+b_sp)$. The coefficient $b_s$ includes the bound vibrational partition factor, the translational <thermal de Broglie wavelength>, and the positive binding <Boltzmann factor>. It has inverse-pressure units. Half coverage occurs at $p=1/b_s$; an unspecified $z_s(T)$ prevents a numerical <pressure> scale, but not the functional isotherm.
Back to article page
