# Should I modify ros3 when I add new heterogeneous reactions

**URL:** <https://forum.cmascenter.org/t/should-i-modify-ros3-when-i-add-new-heterogeneous-reactions/4310>\
**Category:** CMAQ\
**Created:** [August 18, 2023, 2:59am UTC](https://forum.cmascenter.org/t/should-i-modify-ros3-when-i-add-new-heterogeneous-reactions/4310 "2023-08-18T02:59:55Z")\
**Posts on this page:** 3\
**Page:** 1

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**Author:** ![LYM](https://avatars.discourse-cdn.com/v4/letter/l/b38774/32.png) [@LYM](https://forum.cmascenter.org/u/LYM)\
**Post date:** [August 18, 2023, 2:59am UTC](https://forum.cmascenter.org/t/should-i-modify-ros3-when-i-add-new-heterogeneous-reactions/4310/1 "2023-08-18T02:59:55Z")

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Hi everyone,

I have added 3 new heterogeneous reactions in mech\_cb6r3\_ae7\_aq.def and updated /CMAQv5.3.2/CCTM/src/MECHS/cb6r3\_ae7\_aq folder through running /UTIL/chemmech. And I also modify AEROSOL\_CHEMISTRY.F. I know that if I use EBI solver, I also need to update /CMAQv5.3.2/CCTM/src/gas/ebi\_cb6r3\_ae7\_aq folder through ruuning /CMAQv5.3.2/UTIL/create\_ebi. But If I use ros3 solver, need I make any change in /CMAQv5.3.2/CCTM/src/gas/ros3 folder?  
Much appreciated for your help!

Best wishes,  
Lingyun

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**Author:** ![gsarwar](https://avatars.discourse-cdn.com/v4/letter/g/5f9b8f/32.png) [@gsarwar](https://forum.cmascenter.org/u/gsarwar)\
**Post date:** [August 22, 2023, 3:12pm UTC](https://forum.cmascenter.org/t/should-i-modify-ros3-when-i-add-new-heterogeneous-reactions/4310/2 "2023-08-22T15:12:39Z")

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> [@LYM](#):
>
> Lingyun

Dear Lingyun,  
You do not need to modify ROS3 and Gear solvers. Both are generalized solvers and you can directly use ROS3 or Gear solver. You will need to compile the model after revising AEROSOL\_CHEMISTRY.F and RXNS\_\* flies.

Thanks,  
Sarwar

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**Author:** ![LYM](https://avatars.discourse-cdn.com/v4/letter/l/b38774/32.png) [@LYM](https://forum.cmascenter.org/u/LYM)\
**Post date:** [August 23, 2023, 6:34pm UTC](https://forum.cmascenter.org/t/should-i-modify-ros3-when-i-add-new-heterogeneous-reactions/4310/3 "2023-08-23T18:34:57Z")

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Dear Sarwar,

Thank you very much for your answer！

Best wishes,  
Lingyun