# How to convert stream file (.str) which is NOT generated fromCGenFF into .itp and .prm file **URL:** \ **Category:** User discussions\ **Created:** [December 17, 2020, 8:38pm UTC](https://gromacs.bioexcel.eu/t/how-to-convert-stream-file-str-which-is-not-generated-fromcgenff-into-itp-and-prm-file/1286 "2020-12-17T20:38:29Z")\ **Posts on this page:** 1\ **Showing post:** 3
**Author:** ![kuj0001](https://avatars.discourse-cdn.com/v4/letter/k/8491ac/32.png) [@kuj0001](https://gromacs.bioexcel.eu/u/kuj0001)\ **Post date:** [December 28, 2020, 9:21pm UTC](https://gromacs.bioexcel.eu/t/how-to-convert-stream-file-str-which-is-not-generated-fromcgenff-into-itp-and-prm-file/1286/3 "2020-12-28T21:21:26Z")
Thank you for the feedback. I am new to MD simulations so I tried to find a protocol that can lead me to understand how to build the topology,but I couldnt find. Do you know where I can find ? Also, I found ffTK in VMD can generate CHARMM parameter file ,so I would like to know can I use cgenff\_charmm2gmx\_py3\_nx2.py` script to convert my parameters obtained with FFTK into GROMACS format? I found here ,someone has done it,[Atom types equivalence between CHARMM36 and AMBER99bsc1](https://gromacs.bioexcel.eu/t/atom-types-equivalence-between-charmm36-and-amber99bsc1/1223) Thank you! Udara --- _[View the full topic](https://gromacs.bioexcel.eu/t/how-to-convert-stream-file-str-which-is-not-generated-fromcgenff-into-itp-and-prm-file/1286)._