Hi,

I am a beginner in using Chimera. I have a simple question for you experts and I really appreciate any guide for me.

I am working on a project needs to create a one-to-one mapping between MRC grid and PDB atoms. For example, from the PDB file, I know the physical coordinates of each atom.  I want to know whether each atom is out of the 3D volume of MRC or not.  If it is inside the volume, I hope to know which voxel grid this atom is in.

I have figured out the mapping between the physical origin of PDB system and its grid index in MRC using Chimera Volume Viewer -- > Features ---> Coordinates ----> Origin Index.  But I am not sure whether the information of ‘Rotation axis’ is also very important, which is usually [0,0,1] in  Chimera Volume Viewer -- > Features ---> Coordinates ----> Rotation axis. 

Thank you very much.

Best,

Rongjian