The SCA file extension is related to the PHASES a computing software used to compute phase angels.
SCA file extension - PHASES SCALEPACK file
What is sca file? How to open sca files?
File type specification:
The SCA file extension is associated with the PHASES a package of computer programs used to compute phase angels for diffraction data from macromolecular crystals. The .sca file stores various data used for internal purposes of PHASES.