LaTeX导入多行公式编号混乱

[JackYansongLi]

进入数学模式后利用 ctrl/cmd+shift+v 粘贴如下 命令 可观察到编号的排版混乱 （掉到下排了）

\begin{equation}
\begin{aligned}
\sigma^\text{qi} (B \rightarrow 0) &= \frac{e^2}{4 \pi h}\sum_{i = s,
t_{\pm}} w_i \bigg[ \psi \Big( \frac{\ell_B^2}{\ell_i^2} +
\frac{\ell_B^2}{\ell_e^2} + \frac{1}{2}\Big) - \psi \Big(
\frac{\ell_B^2}{\ell_i^2} + \frac{\ell_B^2}{\ell_{\phi }^2} + \frac{1}{2}
\Big) \bigg] \Big|_{\ell_B \rightarrow \infty}\\
&= \frac{e^2}{4\pi h}\sum_{i = s, t_{\pm}} w_i \bigg[ \ln \Big(
\frac{\ell_B^2}{\ell_i^2} + \frac{\ell_B^2}{\ell_e^2}\Big) - \ln
\Big( \frac{\ell_B^2}{\ell_i^2} + \frac{\ell_B^2}{\ell_{\phi }^2}
\Big) \bigg]\\
&= \frac{e^2}{4 \pi h}\sum_{i = s, t_{\pm}} w_i \ln \frac{\ell_i^{- 2}
+ \ell_e^{- 2}}{\ell_i^{- 2} + \ell_{\phi}^{- 2}} .
\end{aligned}
\end{equation}

[JackYansongLi]

这个的问题根源在 equation 环境内 输入 aligned，再对equation编号应当处在右方正中间，这块我们的处理有问题。正确情况如图

对应代码

\begin{equation}
  \begin{aligned}
    f(x) & = x^2 \\
         & = x^3
  \end{aligned}
\end{equation}