\documentclass[11pt,a4paper]{article}
\usepackage[utf8]{inputenc}
\usepackage[catalan]{babel}
\usepackage{fancyhdr}
\usepackage{graphicx}
\usepackage[labelfont=bf]{caption}
\usepackage{siunitx}
\usepackage{geometry}
\geometry{top=25mm}
\usepackage{amsmath}
\usepackage{amsfonts}
\usepackage{booktabs}
\usepackage{chemformula}
\usepackage{multicol}
%\usepackage{hyperref} %TODO: Uncomment
\usepackage{biblatex}
\usepackage{pgfplotstable}
\usepackage{adjustbox}
\usepackage{array}
\usepackage{float}
\usepackage{stackengine}

\newcolumntype{L}[1]{>{\raggedright\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{C}[1]{>{\centering\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}
\newcolumntype{R}[1]{>{\raggedleft\let\newline\\\arraybackslash\hspace{0pt}}m{#1}}

\pgfplotsset{compat=1.16}
\pgfplotstableset{
  empty cells with={--}, % replace empty cells with ’--’
  every head row/.style={before row=\toprule,after row=\midrule},
  every last row/.style={after row=\bottomrule},
  set thousands separator={\,}%,
}
\sisetup{separate-uncertainty=true}
\setlength{\parskip}{1em}
\pagestyle{fancy}
\fancyhf{}

% Plantilles del notate
\def\myupbracefill#1{\rotatebox{90}{\stretchto{\{}{#1}}}
\def\rlwd{.5pt}
\newcommand\notate[4][B]{%
  \if B#1\else\def\myupbracefill##1{}\fi%
  \def\useanchorwidth{T}%
  \setbox0=\hbox{$\displaystyle#2$}%
  \def\stackalignment{c}\stackunder[-6pt]{%
    \def\stackalignment{c}\stackunder[-1.5pt]{%
      \stackunder[2pt]{\strut $\displaystyle#2$}{\myupbracefill{\wd0}}}{%
    \rule{\rlwd}{#3\baselineskip}}}{%
  \strut\kern9pt$\rightarrow$\smash{\rlap{$~#4$}}}%
}
\newcommand\lnotate[4][B]{%
  \if B#1\else\def\myupbracefill##1{}\fi%
  \def\useanchorwidth{T}%
  \setbox0=\hbox{$\displaystyle#2$}%
  \def\stackalignment{c}\stackunder[-6pt]{%
    \def\stackalignment{c}\stackunder[-1.5pt]{%
      \stackunder[2pt]{\strut $\displaystyle#2$}{\myupbracefill{\wd0}}}{%
    \rule{\rlwd}{#3\baselineskip}}}{%
  \strut\kern-9pt$\leftarrow$\smash{\llap{$~#4\quad\;\,$}}}%
}