Hello: Two not new questions. (1) I am trying to read prmtop/mdcrd files from Amber MD with chimera alpha version 1.5 (build 30702) 2010-06-10 23:51:24 GMT, getting "index out of range" (the files are correct, they open with VMD) MDTools 1.2 Exp (2005-08-20) by James Phillips. Trajectory.DCD.MDToolsMarch97.md.help() for more info. - HomoCoord 1.3 Exp (2005-08-20) - Constants 1.1 Exp (2004-05-17) - AtomGroup 1.4 Exp (2007-02-07) - local 1.1 Exp (2004-05-17) Unknown OSTYPE ??? set. Viewing and plotting are disabled. - Trans 1.2 Exp (2005-08-20) - DCD 1.10 Exp (2007-02-07) - Data 1.2 Exp (2005-08-20) Traceback (most recent call last): File "/usr/local/chimera/lib/python2.6/site-packages/Pmw/Pmw_1_3/lib/PmwBase.py", line 1747, in __call__ return apply(self.func, args) File "/usr/local/chimera/share/chimera/baseDialog.py", line 342, in command getattr(s, buttonFuncName(txt))() File "/usr/local/chimera/share/chimera/baseDialog.py", line 560, in OK self.Apply() File "/usr/local/chimera/share/Trajectory/EnsembleLoader.py", line 92, in Apply self.callback) File "/usr/local/chimera/share/Trajectory/DCD/__init__.py", line 72, in loadEnsemble addTrajKw=self.addTrajKw) File "/usr/local/chimera/share/Trajectory/DCD/__init__.py", line 85, in loadEnsemble ensemble = DCD(psf, dcd, startFrame, endFrame) File "/usr/local/chimera/share/Trajectory/DCD/DCD.py", line 24, in __init__ mdtMol = md.Molecule(psf=psfPath) File "/usr/local/chimera/share/Trajectory/DCD/MDToolsMarch97/md_AtomGroup.py", line 356, in __init__ nrecs = int(psfrec[0]) IndexError: list index out of range IndexError: list index out of range File "/usr/local/chimera/share/Trajectory/DCD/MDToolsMarch97/md_AtomGroup.py", line 356, in __init__ nrecs = int(psfrec[0]) See reply log for Python traceback. ************************************************ (2) Although I suppose I used in the past ATOM ATTRIBUTES to display chloride anion at its standard radius in preparing figures for publication, I just get it now as a tiny dot as set by MODELLER. That with proteins without or with non-polar hydrogens. For example TER 6750 LYS A 426 ATOM 6751 Cl- Cl- A 427 -31.021 4.748 41.205 1.00 6.32 Cl TER 6752 Cl- A 427 ATOM 6753 N LEU B 1 -13.959 20.979 -35.226 1.00 63.95 N I can't remember how to specify the chloride radius in command sel :427@Cl- ************************************************ Thanks for pointing me to the correct procedure francesco pietra