\documentstyle[a4,12pt]{article}\pagestyle{empty}\textwidth 15cm\topmargin  0.0cm\oddsidemargin 0.0cm % Text normally has 3cm margin on left.\textheight 24cm\begin{document}\parskip 12pt\parindent 0cmREFCEL is a program to refine the lattice constants for a given celltype or to refine the wavelength. In addition, a 2-theta zero-pointmay be refined. REFCEL requires an input file containing the followinginformation. All input is free format. All lines are keyworded and mustbe given in the order below. The program may be run interactively.\begin{center}\begin{tabular}{ll}{\tt TITLE} & A title line of up to 75 characters.\\\\{\tt LATT} & An integer specifying the cell type.\\\\&\begin{tabular}{cl}1 &  Triclinic \\2 &  Monoclinic (b unique) \\3 &  Monoclinic (c unique) \\4 &  Orthorhombic \\5 &  Tetragonal \\6 &  Cubic \\7 &  Trigonal \& Hexagonal \\8 &  Rhombohedral \\9 &  Monoclinic (a unique) \\\end{tabular}\\\\{\tt CELL} & The lattice parameters $a$ $b$ $c$ $\alpha$ $\beta$ $\gamma$.\\\\{\tt WAVE} & The wavelength in {\AA}ngstroms.\\\\{\tt ZERO} & The $2\theta$ zero-point error.[N.B. $2\theta$(Obs) = $2\theta$(Calc) + Zero]\\\\{\tt VARY} & Refinement flags for wavelength (0 or 1) and zero-point (0 or 1).\\\\{\tt HKL}  & $h_1$ $k_1$ $l_1$ $2\theta_1$ $[\sigma(2\theta_1)]$\\{\tt HKL}  & $h_2$ $k_2$ $l_2$ $2\theta_2$ $[\sigma(2\theta_2)]$\\\ldots & etc.\\\end{tabular}\end{center}The error value is optional and by default is set to 0.01.If an error is specified for the first reflection in thelist, it will be used for all subsequent reflectionswhere the error is not specified. Negative 2-theta valuesmay be used. The list of $hkl$ values is terminated with a blank line orend-of-file.\end{document}