\documentclass[10pt]{article}
\usepackage[utf8]{inputenc}
\usepackage[OT4]{fontenc}
\usepackage{lmodern}
\usepackage{mathtools}
\DeclarePairedDelimiter\bra{\langle}{\rvert}
\DeclarePairedDelimiter\ket{\lvert}{\rangle}
\DeclarePairedDelimiterX\braket[2]{\langle}{\rangle}{#1 \delimsize\vert #2}
\usepackage[a4paper,bindingoffset=0.2in,%
            left=0.75in,right=0.75in,top=1in,bottom=1in,%
            footskip=.25in]{geometry}
\numberwithin{equation}{section}
\renewcommand{\partname}{}
\renewcommand{\thepart}{}
\newcommand{\boldm}[1] {\mathversion{bold}#1\mathversion{normal}}
\begin{document}

\end{document}