Real Cell
Real-Space Unit Cell and Real-Space Cell Angle
realcell and realang define the real-space dimensions of the vectors that describe the unit cell of the protein crystal. This concerns the biological sample, as it swims in the Eppendorf cup. It has (almost) nothing to do with your image. The real-space unit cell dimensions are given in Angstroms, the included angle between the vectors a and b is given in degrees. Bacteriorodopsin for example has real-cell vector lengths of 57.9 Angstroms for a and b, and an included angle of 120 degrees. By convention, the real-space angle has to be equal or LARGER than 90 degrees. (The reciprocal space angle is then equal or smaller 90 degrees.)
Real Unit Cell Length (for entire project) [realcell]
Vector lengths of the real-space unit cell, in Angstrom. This is the dimension of the real physical crystal. These dimensions don't change if the crystal is tilted. This parameter is by default synchronized for the entire crystal project.
Real Cell Angle (for entire project) [realang]
Included angle in the real-space lattice, in deg, (>= 90.0). This is the angle in the physical sample. This is independent of any sample tilt. This parameter is by default synchronized for the entire crystal project.
Local Real Unit Cell Length (only for this image) [realcell_local]
Same as realcell, but as the name states this parameter is local, therefore it will not be synchronized. It is calculated from this image only.
Real Cell Angle (only for this image) [realang_local]
Same as realang, but as the name states this parameter is local, therefore it will not be synchronized. It is calculated from this image only.