\usepackage[T1]{fontenc}
\usepackage{amsmath}
\usepackage{amssymb}
+\usepackage{bm}
\usepackage{ae}
\usepackage{aecompl}
\usepackage[dvips]{graphicx}
\newcommand{\dista}[1]{\unit[#1]{\AA}{}}
\newcommand{\perc}[1]{\unit[#1]{\%}{}}
+%\newcommand{\bra}[1]{\left\langle #1 \right|}
+%\newcommand{\ket}[1]{\left| #1 \right\rangle}
+%\newcommand{\braket}[2]{\left\langle #1 \mid #2 \right\rangle}
\newcommand{\bra}[1]{\langle #1 |}
\newcommand{\ket}[1]{| #1 \rangle}
\newcommand{\braket}[2]{\langle #1 | #2 \rangle}
\newcommand{\RM}[1]{\MakeUppercase{\romannumeral #1{}}}
% vectors are simply represented by bold font characters
-\renewcommand{\vec}[1]{{\bf #1{}}}
+\renewcommand{\vec}[1]{{\bm #1{}}}
%
% theorem environment