Working in Q-Space

The diffractometer software allows the user to move in q space (in reciprocal cell units - not in 1/Angstr.) and to handle the four-circle angles: $two\_theta$, $\omega$, $\chi$ and $\phi$. This is a list of the commands that start the different tasks.

The diffractometer angles are transformed to q-space with the help of the UB matrix, coded by Th. Brückel (now at Forschungszentrum Jülich). ONLINE supplies the code that allows you to create and modify a UB matrix for a specific crystal. The command

ONLINE> create/ub name
creates a new queue element of the type UB. It does not contain only the values of the matrix element but also further information which will be described below. A UB queue element can be read from a file:
ONLINE> read/gqe $<$online_dir$>$ub_matrix_name
The UB matrix queue elements should always be kept in/online_dir. A modified UB queue element is written to disk by:
ONLINE> write/gqe/file=online_dir:ub_matrix_name internal_name



Subsections