Question about ANH4I sensitivity to NH3 in CMAQ5.2 DDM is zero

I am still a beginner in using CMAQ-DDM-3D and I have run successfully. Recently I meet some trouble.
I want to obtain the sensitivity of PM25 to NH3, so I need to know the sensitivity of ANH4I and ANH4J to NH3, but when i successfully run the DDM. Both ANH4I_ENH and ANH4J_ENH are 0. So I can’t get the true value of ANH4I_ENH and ANH4J_ENH (Because ammonia is an important prerequisite for PM25,so it’s sensitivity is not going to be zero) .But I don’t know what led to this problem, because the sensitivity of other species to NH3 is valuable, such as O3_ENH. The sensitivity of NH3 can be set as follows(sensinput.dat file). The above is the problem I have encountered ,
I will appreciate your help!


Please try running a sensitivity to NH3 on the provided test domain and see if you still get zeros there. Also, is there a particular reason you are using version 5.2?