答案1
有多种方法可以实现这一点:
\documentclass{article}
\usepackage{amsmath,siunitx}
\begin{document}
Using \verb|align*|:
\begin{align*}
E_n = \frac{n^2h^2}{8m_{e^{-}}L^2} & & L = 4 \times d_{\text{c-c}} = 5.64\si{\angstrom} \\
& E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2}
\end{align*}
Using \verb|gather*| (1):
\begin{gather*}
E_n = \frac{n^2h^2}{8m_{e^{-}}L^2} \qquad L = 4 \times d_{\text{c-c}} = 5.64\si{\angstrom} \\
E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2}
\end{gather*}
Using \verb|gather*| (2):
\begin{gather*}
E_n = \frac{n^2h^2}{8m_{e^{-}}L^2} \quad
\phantom{E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2}} \quad
L = 4 \times d_{\text{c-c}} = 5.64\si{\angstrom} \\
\phantom{E_n = \frac{n^2h^2}{8m_{e^{-}}L^2}} \quad
E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2} \quad
\phantom{L = 4 \times d_{\text{c-c}} = 5.64\si{\angstrom}}
\end{gather*}
Using \verb|alignat*|:
\begin{alignat*}{3}
E_n = \frac{n^2h^2}{8m_{e^{-}}L^2} & & L = 4 \times d_{\text{c-c}} = 5.64\si{\angstrom} \\
& \quad E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2} \quad
\end{alignat*}
Using an \verb|array|:
\begin{equation*}
\renewcommand{\arraystretch}{2}
\begin{array}{ *{3}{c} }
\displaystyle E_n = \frac{n^2h^2}{8m_{e^{-}}L^2} & & L = 4 \times d_{\text{c-c}} = 5.64\si{\angstrom} \\
& \displaystyle E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2}
\end{array}
\end{equation*}
\end{document}
答案2
您可以使用以下alignat
环境:
\documentclass{article}
\usepackage[utf8]{inputenc}
\usepackage[T1]{fontenc} % Fontencoding: 7bit -> 8bit
\usepackage{lmodern}
\usepackage{amsmath}
\begin{document}
\begin{alignat*}{2}
E_n = \frac{n^2h^2}{8m_{e^{-}}L^2} & & L=4\times d_{\text{c-c}}=5.64\\
&E_1 = \frac{1^2h^2}{8m_{e^{-}}5.46^2}&
\end{alignat*}
\end{document}
但请注意,这会将下面的方程置于上面两个方程之间的间隙中。它实际上并没有将其置于中心。特别是,如果方程很长,则第一个方程之间会有很大的空间。