Hi, I tried to build a wedge volume in gate 6.1 using the following command: /gate/SPECThead/daughters/name crystal /gate/SPECThead/daughters/insert wedge /gate/crystal/geometry/setXLength 52 mm Gate gave the following error: ***** COMMAND NOT FOUND </gate/crystal/geometry/setXLength 52 mm> ***** Please help me in this. Thank you. Shruti