Guided structure refinement using Crystals Validation via Cambridge database: geometry checking
To students and new users, every structure must seem like a new structure type. Thus using CSD geometry check can encourage students to look for errors or novel features of the structure.
RED="too long" and BLUE="too short".
RED ---- GREY ---- GREY ---- BLUE
3sigma 2sigma 1sigma 0sigma 1sigma 2sigma 3sigma