# Aligning two equations horizontally with different numbers, without using \align

Basically, I am using an IoP template for my MPhys report, which for some reason is not keen on me using \align.

This is currently what I have;

equations 12 & 13 are aligned properly, but 14 & 15 are not aligned horizontally properly.

The code I have is;

\usepackage{iopams}
\usepackage{geometry}
\usepackage{graphicx}
\usepackage{caption}
\usepackage{subcaption}
\usepackage{tabularx}
\usepackage{xfrac}

\noindent\begin{tabularx}{\textwidth}{@{}XX@{}}
$$\hspace{-1.5cm} r = \frac{ r_{01} + r_{12}e^{2i \beta} }{{ 1 + r_{01}r_{12}e^{2i \beta}}} \label{eqn:ref}$$ &
$$\hspace{-1.5cm} t = \frac{ t_{01}t_{12}e^{2i \beta} }{{ 1 + r_{01}r_{12}e^{2i \beta}}} , \label{eqn:trans}$$
\end{tabularx}

text

\noindent\begin{tabularx}{\textwidth}{@{}XXX@{}}
\begin{eqnarray}
\hspace{-1.8cm}  R = |r|^2
\label{eqn:R}
\end{eqnarray} &
\begin{eqnarray}
\hspace{-1.5cm} T = \frac{n_2 cos(\theta_2)}{n_1 cos(\theta_1)}|t|^2 ,
\label{eqn:T}
\end{eqnarray}
\end{tabularx}

I was using before, but that wasn't working so tried to use eqnarray. There do seem to be a few similar questions on Tex, but I can't seem to find one that allows me to do what I want without using \align.

I just figured out a workaround, which is to basically make both equations the same size, by using

\vphantom{\frac{n_2 cos(\theta_2)}{n_1 cos(\theta_1)}}

which creates a "phantom" fraction so both equations contain a fraction, so become aligned.

column type m{...} from package array can be of help:

\documentclass{article}
\usepackage{array}

\begin{document}
\noindent%
\begin{tabular}{@{}*{2}{m{\dimexpr0.5\linewidth-2\tabcolsep\relax}}@{}}
$$r = \frac{ r_{01} + r_{12}\exp^{2i \beta} } { 1 + r_{01}r_{12}e^{2i \beta}} \label{eqn:ref}$$
&
$$t = \frac{ t_{01}t_{12}e^{2i \beta} } { 1 + r_{01}r_{12}e^{2i \beta}} , \label{eqn:trans}$$
\end{tabular}

and

\noindent%
\begin{tabular}{@{}*{2}{m{\dimexpr0.5\linewidth-2\tabcolsep\relax}}@{}}
$$R = |r|^2 \label{eqn:R}$$
&
$$T = \frac{n_2 cos(\theta_2)}{n_1 cos(\theta_1)}|t|^2 , \label{eqn:T}$$
\end{tabular}
\end{document}