如何在 LaTeX 中生成此 Aufbau/Hund 图？

Question

如何在 LaTeX 中生成此 Aufbau/Hund 图？

我更喜欢 Chemfig，但 TikZ 似乎更适合。

Answer 1

使用 TikZ：

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{fit}
\usepackage{amssymb,graphicx}

\begin{document}
\begin{tikzpicture}[
     node distance = 0 and 9mm,
          C/.style = {circle, draw, thick},
every label/.style = {align=center}
                    ]
\node (c1) [C,label=below: orbitale pieno]
                                {\rotatebox{90}{$\rightleftarrows$}};
\node (c2) [C,right=22mm of c1] {\rotatebox{90}{$\rightarrow$}};
\node (c3) [C,right=of c2]      {\rotatebox{90}{$\roghtarrow$}};
\node[label=below:elettreoni spaiati\\ con spin paralleli,
      fit=(c2) (c3)] {};
\end{tikzpicture}
\end{document}

附录： 使用 TikZ arrows（由库 arrows.meta 定义）和小图片的解决方案pic：

\documentclass[tikz,border=3mm]{standalone}
\usetikzlibrary{arrows.meta, fit, positioning}

\begin{document}

\begin{tikzpicture}[
     node distance = 0 and 9mm,
        CAA/.pic = {\draw[-Stealth,thick] (-1mm,-3mm) -- + (0,6mm);
                    \draw[Stealth-,thick] ( 1mm,-3mm) -- + (0,6mm); 
                    \node[circle, draw, thick, minimum size=8mm,
                          node contents={}, label=below:#1];
                    \coordinate (-center)   at (0,0);
                    \coordinate (-top)      at (0, 4mm);
                    \coordinate (-bottom)   at (0,-4mm);
                    },
         CA/.pic = {\draw[-Stealth,thick] (0mm,-3mm) -- + (0,6mm);
                    \node[circle, draw, thick, minimum size=8mm,
                          node contents={#1}];
                    \coordinate (-center) at (0,0);
                    \coordinate (-top)      at (0, 4mm);
                    \coordinate (-bottom)   at (0,-4mm);
                    },
every label/.style = {align=center}
                    ]
\pic (c1) at (0,0) {CAA={orbitale pieno}};
\pic (c2) at (3,0) {CA};
\pic (c3) at (4,0) {CA};
\node[label=below:elettreoni spaiati\\ con spin paralleli,
      inner sep=0pt, fit=(c2-top) (c3-bottom)] {};
\end{tikzpicture}
\end{document}