Or can we report a structure with an RMS gradient of 1 x 10 power -4? During full optimization of metal complex (from IRC), I end up with a proton shifted structure (between ligands). This proton shifted structure is not what I want. Before this proton shifting occurs, the original structure goes down to an RMS as low as 1 x 10 power -4. How can I solve this problem? Maybe optimizing under loose conditions? Or some special IOp keywords?