Hi Yuhong, Those numbers are the grid dimensions of the map file: how many grid points (density values) it contains in the X, Y, and Z directions. For example, in your figure: fishmonomer4.mrc has 88 grid points along X, 66 along Y, 94 along Z (total number of values 88 x 66 x 94) 1akeA_10A.mrc has 22 values along X, 22 along Y, 22 along Z (total number of values 22 x 22 x 22) I hope this helps, Elaine ---------- Elaine C. Meng, Ph.D. UCSF Computer Graphics Lab (Chimera team) and Babbitt Lab Department of Pharmaceutical Chemistry University of California, San Francisco On Apr 29, 2012, at 8:06 PM, Yuhong Li wrote:

Dear Chimera developers, Hi! I am a student from Sun Yat-Sen University. I recently began using the Chimera for my study, but I have a problem about how to read the displayed information in volume viewer. Here I attach a picture and inside the picture there are two places I've point out with arrows which represent two different map files in mrc fornat. Now I was wondering if you could spare some time to explain it to me that what do those different numbers mean? Hope to hear from your reply in very soon. Best Wishes, Yuhong Lee