# Mtz2hkl

mtzhkl can be used to convert mtz-files to hkl-format suitable for input to SHELXL. The program attempts to guess all required information from the mtz-file in order to minimise user interaction. So simply typing

mtz2hkl mydata.mtz


creates a file mydata.hkl suitable for input to SHELXL.

If not all information could be uniquely determined from the mtz-file (e.g. because several data columns are present), the program prints short usage instructions and exits.

While CCP4 programs usually use amplitudes, SHELXL refines against either intensities or amplitudes. It is recommended to use intensities and therefore one should make sure the conversion from intensities to amplitudes (often done with truncate) keeps the original intensities in the output [[file-formats#mtz|mtz]-file.

If this is not the case, the option '-2' in mtz2hkl converts amplitudes back to intensities by squaring the amplitudes and converting the standard deviations according to $\sigma_{I} = 2|F|\sigma_{F} = |\frac{\partial I}{\partial F}| \sigma_{F}$.