Hi Bartek, Although the Unit Cell tool generates only a single unit cell, the Multiscale Models tool can generate a 3x3x3 block of unit cells. It is under Tools... Higher-Order Structure. Choose the Multimer option "3x3x3 crystal unit cells" and then click "Make models". See the man page for more details on Multiscale Models: http://www.cgl.ucsf.edu/chimera/docs/ContributedSoftware/multiscale/ framemulti.html A possibly tricky thing is that for computational expediency, Multiscale Models first generates only low-resolution surfaces for all the additional copies. If you need atomic coordinates for some or all of those copies, select those copies in Multiscale Models and then choose a different Style of display. All the styles other than Surface force loading of the atomic coordinates (Ribbon, Wire, Stick, Ball&Stick, Sphere). Loading coordinates for the copies creates additional molecule models in Chimera. Their coordinates can be saved to file(s) with File... Save PDB in the main Chimera menu. I hope this helps, Elaine ----- Elaine C. Meng, Ph.D. meng@cgl.ucsf.edu UCSF Computer Graphics Lab and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco http://www.cgl.ucsf.edu/home/meng/index.html On Jun 19, 2007, at 7:22 AM, Bartosz Siemiński wrote:

Hi all, I was working with Chimera for some time, beeing convinced I don't need no help, until I'd got to this. Is there a possibility of conjoining several (let's say four, nine or sixteen) unit cells? I use the el. density map (converted to cpp4, so it could be loaded by Chimera) for structural alignment and such an operation would be very usefull. Thanks in advance, Bartek