\Section[
    \eng{Band theory}
    \ger{Bändermodell}
]{band}
    \Subsection[
        \eng{Hybrid orbitals}
        \ger{Hybridorbitale}
    ]{hybrid_orbitals}  
    \begin{ttext}
        \eng{Hybrid orbitals are linear combinations of other atomic orbitals.}
        \ger{Hybridorbitale werden durch Linearkombinationen von anderen atomorbitalen gebildet.}
    \end{ttext}

    % chemmacros package
    \begin{formula}{sp3}
        \desc{sp3 Orbital}{\GT{eg} \ce{CH4}}{}
        \desc[german]{sp3 Orbital}{}{}
        \eq{
            1\text{s} + 3\text{p} = \text{sp3}
            \orbital{sp3}
        }
    \end{formula}
    \begin{formula}{sp2}
        \desc{sp2 Orbital}{}{}
        \desc[german]{sp2 Orbital}{}{}
        \eq{
            1\text{s} + 2\text{p} = \text{sp2}
            \orbital{sp2}
        }
    \end{formula}
    \begin{formula}{sp}
        \desc{sp Orbital}{}{}
        \desc[german]{sp Orbital}{}{}
        \eq{
            1\text{s} + 1\text{p} = \text{sp}
            \orbital{sp}
        }
    \end{formula}



\Section[
    \eng{Diffusion}
    \ger{Diffusion}
]{diffusion}    
    \begin{formula}{diffusion_coefficient}
        \desc{Diffusion coefficient}{}{}
        \desc[german]{Diffusionskoeffizient}{}{}
        \quantity{D}{\m^2\per\s}{s}
    \end{formula}

    \begin{formula}{particle_current_density}
        \desc{Particle current density}{Number of particles through an area}{}
        \desc[german]{Teilchenstromdichte}{Anzahl der Teilchen durch eine Fläche}{}
        \quantity{J}{1\per\s^2}{s}
    \end{formula}

    \begin{formula}{einstein_relation}
        \desc{Einstein relation}{Classical}{\QtyRef{diffusion_coefficient}, \mu \qtyRef{mobility}, \QtyRef{temperature}, $q$ \qtyRef{charge}}
        \desc[german]{Einsteinrelation}{Klassisch}{}
        \eq{D = \frac{\mu \kB T}{q}}
    \end{formula}   

    \begin{formula}{concentration}
        \desc{Concentration}{A quantity per volume}{}
        \desc[german]{Konzentration}{Eine Größe pro Volumen}{}
        \quantity{c}{x\per\m^3}{s}
    \end{formula}

    \begin{formula}{fick_law_1}
        \desc{Fick's first law}{Particle movement is proportional to concentration gradient}{\QtyRef{particle_current_density}, \QtyRef{diffusion_coefficient}, \QtyRef{concentration}}
        \desc[german]{Erstes Ficksches Gesetz}{Teilchenbewegung ist proportional zum Konzentrationsgradienten}{}
        \eq{J = -D\frac{c}{x}}
    \end{formula}

    \begin{formula}{fick_law_2}
        \desc{Fick's second law}{}{\QtyRef{particle_current_density}, \QtyRef{diffusion_coefficient}, \QtyRef{concentration}}
        \desc[german]{Zweites Ficksches Gesetz}{}{}
        \eq{\pdv{c}{t} = D \pdv[2]{c}{x}}
    \end{formula}

\Section[
    \eng{\GT{misc}}
    \ger{\GT{misc}}
]{misc}



    \begin{formula}{work_function}
        \desc{Work function}{Lowest energy required to remove an electron into the vacuum}{}
        \desc[german]{Austrittsarbeit}{eng. "Work function"; minimale Energie um ein Elektron aus dem Festkörper zu lösen}{}
        \quantity{W}{\eV}{s}
        \eq{W = \Evac - \EFermi}
    \end{formula}

    \begin{formula}{electron_affinity}
        \desc{Electron affinity}{Energy required to remove one electron from an anion with one negative charge.\\Energy difference between vacuum level and conduction band}{}
        \desc[german]{Elektronenaffinität}{Energie, die benötigt wird um ein Elektron aus einem einfach-negativ geladenen Anion zu entfernen. Entspricht der Energiedifferenz zwischen Vakuum-Niveau und dem Leitungsband}{}
        \quantity{\chi}{\eV}{s}
        \eq{\chi = \left(\Evac - \Econd\right)}
    \end{formula}


    \begin{formula}{laser}
        \desc{Laser}{Light amplification by stimulated emission of radiation}{}
        \desc[german]{Laser}{}{}
        \ttxt{
            \eng{\textit{Gain medium} is energized \textit{pumping energy} (electric current or light), light of certain wavelength is amplified in the gain medium}
        }
    \end{formula}