Silica and Alumina polyhedrons using Tikz

Question

Does anyone has code examples on how to draw silica tetrahedron and alumina octahedron. I need to include them in my beamer presentation. Graphics are not so good. So I would like to draw them using Tikz.

Answer 1

Update I follow this link

// silica (regular) tetradhedron
unitsize(8mm);
import solids;
import three;
currentprojection=orthographic(2,1.5,5,zoom=.9,center=true);
triple A=(1,0,0), B=(0,1,0), C=(0,0,1), D=(1,1,1); // for 4 oxygen atoms
triple Si=(.5,.5,.5);  // for 1 silicon atom
triple[] points={A,B,C,D};
for(var p : points){
draw(surface(sphere(p,.2)),red);
draw(Si--(Si+p)/2,gray+4pt);
draw(p--(Si+p)/2,red+4pt);
}
draw(surface(sphere(Si,.2)),gray);

For silica tetrahedron, we can illustrate with a regular tetrahedron. Feel free to choose another view with currentprojection.

Run on http://asymptote.ualberta.ca/

// silica (regular) tetradhedron
unitsize(5cm);
import solids;
import three;
currentprojection=orthographic(2,1.5,5,zoom=.9,center=true);
triple A=(1,0,0), B=(0,1,0), C=(0,0,1), D=(1,1,1); // for 4 oxygen atoms
triple Si=(.5,.5,.5);  // for 1 silicon atom
draw(A--B--C--D--cycle^^A--C^^B--D,gray+3pt);
draw(Si--A^^Si--B^^Si--C^^Si--D,magenta+10pt);
triple[] points={A,B,C,D};
for(var p : points)
draw(surface(sphere(p,.1)),red);
draw(surface(sphere(Si,.15)),orange);
// to see how I draw a regular tetradhedron
//draw(unitbox,lightgray);
//dot(O,red);

Answer 2

Another TikZ option.

I use the calc library to find the edges ends (where they intersect with the atoms). Then, the order in which the various elements are drawn is the key to visibility.

\documentclass [tikz,border=2mm]{standalone}
\usetikzlibrary{3d,calc,perspective}
\tikzset
{% Styles
    O atom/.style={shading=ball,ball color=red},
   Si atom/.style={shading=ball,ball color=gray},
      edge/.style={ultra thick},
      bond/.style={ultra thick,blue}
}
\begin{document}
\begin{tikzpicture}[line cap=round,isometric view,rotate around z=-50]
% dimensions
\def\bd{3}                         % bond distance Si-O (center to center)
\pgfmathsetmacro\el{4/sqrt(6)\bd} % edge length (tetrahedron)
\pgfmathsetmacro\ba{acos(-1/3)}    % bond angle
\def\rO{0.3}                       % radius, oxigen
\pgfmathsetmacro\rSi{11/6\rO}     % radius, silicon
% coordinates
\foreach[count=\ii]\i in {A,B,C}
{
  \begin{scope}[rotate around z=240-120*\ii,canvas is xz plane at y=0]
    \coordinate (\i0) at (90-\ba:\bd);     % center  O
    \coordinate (\i1) at (90-\ba:\bd-\rO); % surface O
    \coordinate (\i2) at (90-\ba:\rSi);    % surface Si
  \end{scope}
}
\coordinate (D0) at (0,0,\bd);             % center  O
\coordinate (D1) at (0,0,\bd-\rO);         % surface O
\coordinate (D2) at (0,0,\rSi);            % surface Si
\coordinate (O)  at (0,0,0);               % center  Si
% atoms, bonds and tetrahedron
\draw[O atom]  (A0) circle (\rO cm);
\draw[edge]    ($(A0)!\rO/\el!(B0)$) -- (B0);
\draw[edge]    ($(A0)!\rO/\el!(C0)$) -- (C0);
\draw[edge]    ($(A0)!\rO/\el!(D0)$) -- (D0);
\draw[bond]    (A1) -- (A2);
\draw[Si atom] (O)  circle (\rSi cm);
\draw[O atom]  (B0) circle (\rO cm);
\draw[bond]    (B1) -- (B2);
\draw[bond]    (C1) -- (C2);
\draw[bond]    (D1) -- (D2);
\draw[edge]    ($(B0)!\rO/\el!(C0)$) -- (C0);
\draw[edge]    ($(B0)!\rO/\el!(D0)$) -- (D0);
\draw[O atom]  (D0) circle (\rO cm);
\draw[O atom]  (C0) circle (\rO cm);
\draw[edge]    ($(D0)!\rO/\el!(C0)$) -- ($(C0)!\rO/\el!(D0)$);
\end{tikzpicture}
\end{document}

The output:

Update: Improvement of tetrahedron distances, and removing the not too accurate SiO2 label as suggested.

Answer 3

An easy pure Tikz construct of a tetrahedron as a start:

\documentclass[border=1cm]{standalone}
\usepackage{tikz}
\tikzset{
    ball/.style = {circle,shading=ball,minimum width=0.152cm,ball color=gray},
    ball2/.style = {circle,shading=ball,minimum width=0.210cm,ball color=red!40},
    ball3/.style = {circle,shading=ball,minimum width=0.097cm,ball color=green!40},
    ball4/.style = {circle,shading=ball,minimum width=0.184cm,ball color=blue!40},
}
\usepackage{mhchem}
\begin{document}
\begin{tikzpicture}
\node[ball] (A) at (0,0) {};
\node[ball] (B) at (-0.5,1) {};
\node[ball] (C) at (2,0.5) {};
\node[ball] (D) at (0.75,3) {};
\node[ball2] (Si) at (0.75,1.5) {};

\draw[] (A)--(B) -- (A)--(C) (A)--(C) (B)--(D) (A)--(D) (C)--(D);
\draw[dashed] (B)--(C);
%\draw[thick,blue] (A)--(Si) -- (B)--(Si) (C)--(Si) (D)--(Si); % uncomment if you want to have bonds

\node[yshift=-2cm] at (Si) {\ce{[SiO4]^4-}};


\end{tikzpicture}
\begin{tikzpicture}
\node[ball3] (A) at (0,0) {};
\node[ball3] (B) at (3,0) {};
\node[ball3] (C) at (3.75,0.5) {};
\node[ball3] (D) at (4,2.25) {};
\node[ball3] (E) at (1,1.75) {};
\node[ball3] (F) at (1.75,2.25) {};
\node[ball4] (Al) at (2.25,1.25) {};

\draw[] (A)--(E) (A)--(B) (B)--(E) (B)--(C) (C)--(D) (D)--(F) (F)--(E) (E)--(D) (D)--(B);
\draw[dashed,red] (A)--(F) (A)--(C) (C)--(F);

\node[yshift=-2cm] at (Al) {\ce{Al(OH)3}};



\end{tikzpicture}
\end{document}

Reference picture: Source and here