Hi CHARMm users,

I build a system which contains RNA, protein and a membrane with Cholesterol so i need to read in the parameter files for all of the four components (NA, PROT, LIPID, CHOL).

I checked each structure by its own and made sure each works.
But I failed at the point where I want to put the system together. I couldn't manage to read all the required rtf/prm files.

I tried different combinations and orders but no success.
See an example below:

! Read topology and parameter files
open read card unit 10 name para/top_all27_prot_na.rtf
read  rtf card unit 10

open read card unit 20 name para/par_all27_prot_na.prm
read para card unit 20

open read card unit 10 name para/top_all27_lipid.rtf
read  rtf card append unit 10 

open read card unit 20 name para/par_all27_lipid.prm
read para card append unit 20

stream para/toppar_all27_lipid_cholesterol.str

Before I start to post all possible errors I collected I would like to ask if this is the proper way of reading multiple rft/prm files. If not, please let me know how to read all the needed parameters (NA, PROT, LIPID, CHOLESTEROL)

Kind regards