Dir sir I try to write a indenpendent python script and run it from command line some global variables was first set: export LD_LIBRARY_PATH=/home/wascm/chimera/lib:$LD_LIBRARY_PATH export PYTHONPATH=/home/wascm/chimera/share:/home/wascm/chimera/lib:$PYTHONPATH export CHIMERA=/home/wascm/chimera the script work well when import following module import chimera from chimera import runCommand, openModels, MSMSModel from WriteMol2 import writeMol2 from WriteDMS import writeDMS however, when add the code: from DockPrep import prep the error information as follows: ####################################### Traceback (most recent call last): File "./xx.py", line 12, in <module> from DockPrep import prep File "/home/wascm/chimera/share/DockPrep/__init__.py", line 15, in <module> from prefs import prefs, defaults, INCOMPLETE_SC, MEMORIZED_SETTINGS File "/home/wascm/chimera/share/DockPrep/prefs.py", line 13, in <module> from Rotamers.prefs import defaults as rotamerDefaults File "/home/wascm/chimera/share/Rotamers/__init__.py", line 574, in <module> from prefs import defaults, CLASH_METHOD, CLASH_THRESHOLD, HBOND_ALLOWANCE File "/home/wascm/chimera/share/Rotamers/prefs.py", line 13, in <module> from DetectClash.prefs import CLASH_THRESHOLD, HBOND_ALLOWANCE, PB_COLOR, \ File "/home/wascm/chimera/share/DetectClash/__init__.py", line 157, in <module> val = getColorByName(val) File "/home/wascm/chimera/share/chimera/colorTable.py", line 87, in getColorByName color = chimera.MaterialColor(r/255.0, g/255.0, b/255.0) ValueError: missing default material ################################################# how can i solve this problem? best wishes Tao Cui