Hi, I am new in this mailing list but found chimera more useful than any other software. I was building a protein that contain HEME. When I was calculating the charge using chimera interface, then it is asking for HEM[FE] and HEM[nonFE] formal charge. I know chimera is using MMTK and AMBER forcefield. If I will give the default value then it is assigning +2 charge to Fe, which is not a match based on AMBER forcefield.  Meanwhile I try to change the Formal charge manually, but still it gives the same +2 for Fe. Anybody used chimera to prepare a protein having heme for dock or geometry build. 
<br><br>&nbsp;My another question is: Is it possible in chimera to merge nonpolar hydrogen charges on the heavy atoms, the technique used in autodock. <br><br>I will highly appreciate your help and suggestions in this matter.<br>
thanks in advance.<br>s<br><br>