# NAMD+MM\_GBSA/PBSA for per residue energy decomposition

**URL:** <https://gromacs.bioexcel.eu/t/namd-mm-gbsa-pbsa-for-per-residue-energy-decomposition/8625>\
**Category:** User discussions\
**Tags:** analysis-tools\
**Created:** [March 16, 2024, 11:39am UTC](https://gromacs.bioexcel.eu/t/namd-mm-gbsa-pbsa-for-per-residue-energy-decomposition/8625 "2024-03-16T11:39:38Z")\
**Posts on this page:** 1\
**Page:** 1

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**Author:** ![Betsy](https://avatars.discourse-cdn.com/v4/letter/b/e0b2c6/32.png) [@Betsy](https://gromacs.bioexcel.eu/u/Betsy)\
**Post date:** [March 16, 2024, 11:39am UTC](https://gromacs.bioexcel.eu/t/namd-mm-gbsa-pbsa-for-per-residue-energy-decomposition/8625/1 "2024-03-16T11:39:38Z")

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GROMACS version:  
GROMACS modification: Yes/No  
Here post your question  
Hi everynone,  
For the MM\_GBSA/PBSA calculation of NAMD version of trajectory , I used gmx\_MMPBSA/example/psf\_dcd/protein\_protein for testing ([Protein-protein - gmx\_MMPBSA Documentation](https://valdes-tresanco-ms.github.io/gmx_MMPBSA/dev/examples/psf_dcd/protein_protein/)) , but I found that when adding &decomp (idecomp=2, dec\_verbose=3, print\_res=“within 100” ), the energy decomposition of all C-termius backbone of the amino acids is 0, I think this is very abnormal, so I have doubts about the overall energy calculation, has anyone met this problem, how should I solve it? Thanks a lot.

Best wishes,  
Besty