对齐多个方程

Question

我想将多个方程式对齐。但是，我不知道该如何编码。我使用以下序言：

\documentclass[11pt]{article}


%comments
%pdflatex, bibtex, pdflatex, pdflatex

\usepackage{titling}
    \setlength{\droptitle}{-12cm}

\usepackage{graphics, float}
\usepackage[pdftex]{graphicx}
\usepackage{caption}
    \usepackage{subcaption}

\usepackage{siunitx}   %allows SI units by using \SI{unit} 
\usepackage{amsmath}   %allows \begin{equation} \end{equation}

\usepackage{geometry}
\usepackage{changepage}     %allows you to widen or shorten the page width from the left or the right.

因为F_{hkl}我想对齐下面的方程。第二个方程的等号应该放在第一个方程的等号正下方。有人能帮我解决这个问题吗？

我现在正在使用下面的代码，但还不满意。

\begin{equation*}
\mathrm{F_{hkl}} = \mathrm{f_{j}} 
( \operatorname{e} ^ {2\pi \cdot i (h\cdot0 + k\cdot0 + l\cdot0)} + 
\operatorname{e} ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} + l\cdot0)} + 
\operatorname{e} ^ {2\pi  i (h\cdot0 + k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
\operatorname{e} ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot0 + l\cdot\frac{1}{2})} )
\end{equation*}

\begin{equation*}
\mathrm{F_{hkl}} = \mathrm{f_{j}} 
( \operatorname{e} ^ {2\pi i \cdot 0} + 
\operatorname{e} ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} } + 
\operatorname{e} ^ {2\pi  i (k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
\operatorname{e} ^ {2\pi  i (h\cdot\frac{1}{2} + l\cdot\frac{1}{2})} )
\end{equation*}

Answer 1

这种类型的对齐是使用开箱即用的amsmath的align环境：

\documentclass{article}

\usepackage{amsmath}
\newcommand{\ee}{\mathrm{e}}

\begin{document}

\[
  \mathrm{F_{hkl}} = \mathrm{f_{j}} 
  ( \ee ^ {2\pi \cdot i (h\cdot0 + k\cdot0 + l\cdot0)} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} + l\cdot0)} + 
  \ee ^ {2\pi  i (h\cdot0 + k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot0 + l\cdot\frac{1}{2})} )
\]

\[
  \mathrm{F_{hkl}} = \mathrm{f_{j}} 
  ( \ee ^ {2\pi i \cdot 0} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} } + 
  \ee ^ {2\pi  i (k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + l\cdot\frac{1}{2})} )
\]

\begin{align*}
  \mathrm{F_{hkl}} &= \mathrm{f_{j}} 
  ( \ee ^ {2\pi \cdot i (h\cdot0 + k\cdot0 + l\cdot0)} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} + l\cdot0)} + 
  \ee ^ {2\pi  i (h\cdot0 + k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot0 + l\cdot\frac{1}{2})} ) \\
  \mathrm{F_{hkl}} &= \mathrm{f_{j}} 
  ( \ee ^ {2\pi i \cdot 0} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} } + 
  \ee ^ {2\pi  i (k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
  \ee ^ {2\pi  i (h\cdot\frac{1}{2} + l\cdot\frac{1}{2})} )
\end{align*}

\end{document}

使用 确保对齐&=。

Answer 2

除了使用align*环境将两个方程式的=符号对齐之外，您可能还想研究使用mathastext包来避免输入大量的\mathrm“包装器”语句。

\documentclass[11pt]{article}
\usepackage{amsmath} 
\usepackage{geometry}
\usepackage{mathastext}
\begin{document}

\begin{align*}
F_{hkl} &= f_{j} \bigl(
e ^ {2\pi \cdot i (h\cdot0 + k\cdot0 + l\cdot0)} + 
e ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} + l\cdot0)} + 
e ^ {2\pi  i (h\cdot0 + k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
e ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot0 + l\cdot\frac{1}{2})} \bigr)\\
F_{hkl} &= f_{j} \bigl(
e ^ {2\pi i \cdot 0} + 
e ^ {2\pi  i (h\cdot\frac{1}{2} + k\cdot\frac{1}{2} } + 
e ^ {2\pi  i (k\cdot\frac{1}{2} + l\cdot\frac{1}{2})} + 
e ^ {2\pi  i (h\cdot\frac{1}{2} + l\cdot\frac{1}{2})} \bigr)
\end{align*}
\end{document}