Hi Padma, The code for the hkcage command had to be changed for Chimera version 1.2348 and newer because we switched from using the Numeric Python array package to its not completely compatible successor called NumPy. The new code for the hkcage command is on the experimental features web page http://www.cgl.ucsf.edu/chimera/experimental/experimental.html Use that new code with Chimera 1.2363. I have not had time to try flattening an icosahedral map. I made a small step toward another request of yours, plotting radial density. I tried a Python 2-d plotting library called matplotlib that could be used for making radial density plots. It is a pretty big package so we have not decided whether to include it in Chimera. Tom