I have the following text in a `matrix` environment. Is there a better way to format it, say with each column being left ordered, and how can this be done? 

```
$$
\begin{matrix}
\Gamma^{i}_{\mbox{ }0i}=\frac{\dot{a}}{a} \mbox{ ,i from 1..3 }
  & \Gamma^{0}_{\mbox{ }11}=\frac{a\dot{a}}{1-kr^{2}}
  & \Gamma^{0}_{\mbox{ }22}=\dot{a}ar^{2}
  & \Gamma^{0}_{\mbox{ }33}=\dot{a}ar^{2}\sin^{2}{(\theta)}
\\
\Gamma^{1}_{\mbox{ }11}=+\frac{kr}{1-kr^{2}}
  & \Gamma^{1}_{\mbox{ }22}=-r(1-kr^{2})
  & \Gamma^{1}_{\mbox{ }33}=-(1-kr^{2})r\sin^{2}{(\theta)}
  & \Gamma^{2}_{\mbox{ }12}=\frac{1}{r}
\\
\Gamma^{3}_{\mbox{ }23}=\cot{(\theta)}
  & \Gamma^{3}_{\mbox{ }13}=\frac{1}{r}
  & \Gamma^{2}_{\mbox{ }33}=-\sin{(\theta)}\cos{(\theta)}
\end{matrix}
$$

```

![enter image description here](https://i.stack.imgur.com/83qQD.png)