I am trying to minimize a complex[1] and saving it in a pdbqt format. I minimize it in Chimera and saved in pdb[2], followed by using iBabel (GUI of open babel for Mac) to convert pdb into pdbqt.

Here are two things: first, if I convert without using any flag then output gives me pdbqt file with BRANCH information which is not supported by Vina. To solve it I am using -XR flag in iBabel to trim the BRANCH information so that resulting pdbqt file can be read by Vina. But in that case iBabel is giving me weird looking structure and upon inspection of pdbqt file[3] I realized the complex was split into different models. I had successfully followed the same workflow for other minimization code i.e. YASARA. Can anybody please help me to fix it.