extract cnt form nr--help please

dear all
there is an issue occurred: the cnt was extracted out crooked from the natural rubber.
in my “in.file” there are 20 cnt atoms that are grouped as “cntend” then implementing “fix smd” to “cntend”, hopping to extract the cnt out , but things always not like what i expect . in my opinion it is because that the wrong ID of cnt atoms are grouped as “cntend” , but i tried 1:20 or 241:260 as the “cntend”(the total number of cnt atoms is 260) ,both of them were extracted out crooked .do you agree with me ? or do you have some other opinions.
look forward to your reply

hao

dear all
there is an issue occurred: the cnt was extracted out crooked from the natural rubber.
in my “in.file” there are 20 cnt atoms that are grouped as “cntend” then implementing “fix smd” to “cntend”, hopping to extract the cnt out , but things always not like what i expect . in my opinion it is because that the wrong ID of cnt atoms are grouped as “cntend” , but i tried 1:20 or 241:260 as the “cntend”(the total number of cnt atoms is 260) ,both of them were extracted out crooked .do you agree with me ? or do you have some other opinions.

there is not enough information here to have an opinion. how can we know, that any of your input is proper? that your forcefield data is consistent with your topology data and geometry and that pulled with a suitable velocity and that you picked the correct atoms for your purpose?

you can easily verify whether you picked the suitable atoms by writing a dump file for only the group you selected and comparing it with a dump file for all atoms.

axel.