Overlayer

Wood's notation takes the form

${\displaystyle {\text{M}}(hk\ell )-\left({\tfrac {|{\textbf {a}}_{0}|}{|{\textbf {a}}_{s}|}}\times {\tfrac {|{\textbf {b}}_{0}|}{|{\textbf {b}}_{s}|}}\right)-{\text{R}}\alpha ^{\circ }-{\text{A}}}$

where M is the chemical symbol of the substrate, A is the chemical symbol of the overlayer, ${\displaystyle (hk\ell )}$ are the Miller indices of the surface plane, R and ${\displaystyle \alpha }$ correspond to the rotational difference between the substrate and overlayer vectors, and the vector magnitudes shown are those of the substrate (${\displaystyle s}$ subscripts) and of the overlayer (${\displaystyle 0}$ subscripts). This notation can only describe commensurate overlayers however, while matrix notation can describe both.

Matrix notation differs from Wood's notation in the second term, which is replaced by the ${\displaystyle G}$ matrix that describes the overlayer primitive vectors in terms of the substrate primitive vectors:

${\displaystyle {\begin{pmatrix}{\textbf {a}}_{0}\\{\textbf {b}}_{0}\end{pmatrix}}=G{\begin{pmatrix}{\textbf {a}}_{s}\\{\textbf {b}}_{s}\end{pmatrix}}}$, where ${\displaystyle G={\begin{pmatrix}G_{11}&G_{12}\\G_{21}&G_{22}\\\end{pmatrix}}}$

and so hence matrix notation has the form

${\displaystyle {\text{M}}(hk\ell )-G-{\text{R}}\alpha ^{\circ }-{\text{A}}}$

• Kolasinski, Kurt W. (2012). Surface Science: Foundations of Catalysis and Nanoscience (3 ed.). Wiley. ISBN 978-1119990352.
• Attard, Gary; Barnes, Colin (1998). Surfaces. Oxford Chemistry Primers. ISBN 978-0198556862.

• "6.1: Classification of Overlayer Structures". chem.libretexts.org. Retrieved 2019-03-12.