# CMAQv5.4 DDM (split inventories for gridded emissions) **URL:** \ **Category:** CMAQ-DDM-3D\ **Created:** [February 20, 2023, 6:22pm UTC](https://forum.cmascenter.org/t/cmaqv5-4-ddm-split-inventories-for-gridded-emissions/3932 "2023-02-20T18:22:26Z")\ **Posts on this page:** 3\ **Page:** 1
**Author:** ![abi0010](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@abi0010](https://forum.cmascenter.org/u/abi0010)\ **Post date:** [February 20, 2023, 6:22pm UTC](https://forum.cmascenter.org/t/cmaqv5-4-ddm-split-inventories-for-gridded-emissions/3932/1 "2023-02-20T18:22:26Z")
With DDM5.2, a gridded file (with all emissions) would be in the main script and then split inventories (i.e., a custom category of the user’s setup) of gridded files would be listed elsewhere in the run script. With DDM5.4, does one have to list the split gridded inventories instead of a single gridded file (with all the emissions), to assess the sensitivity a particular category. Note, not using the typical sector categories of NEI. The latter suggestion is the way I got it to run but wanted to double check ---
**Author:** ![sergey](https://avatars.discourse-cdn.com/v4/letter/s/9fc348/32.png) [@sergey](https://forum.cmascenter.org/u/sergey)\ **Post date:** [February 21, 2023, 2:28pm UTC](https://forum.cmascenter.org/t/cmaqv5-4-ddm-split-inventories-for-gridded-emissions/3932/2 "2023-02-21T14:28:36Z")
CMAQ 5.4 DDM-3D uses the DESID emissions module definitions. You need to specify all emissions streams in the runscript and they tell the model which ones to use for DDM-3D in the DDM-3D control file. Sergey ---
**Author:** ![abi0010](https://avatars.discourse-cdn.com/v4/letter/a/9fc348/32.png) [@abi0010](https://forum.cmascenter.org/u/abi0010)\ **Post date:** [February 21, 2023, 5:17pm UTC](https://forum.cmascenter.org/t/cmaqv5-4-ddm-split-inventories-for-gridded-emissions/3932/3 "2023-02-21T17:17:11Z")
I see it now. I can use the stream families. Very, very nice feature.