From: sally cii (
Date: Tue Jul 10 2007 - 03:03:23 CDT

Dear all,

I want to select the gas molecules (suppose name GAS) within a specific
distance of one atom FE in a trajectory.

I know if I want to select the gas molecules within a distance I can use
"name GAS and within r of name FE", however,

as I want to select those more than r1 and less than r2 of FE, and in the
trajectory, the coordinates of FE are changing

every frame, so I couldn't use sqr(x-a)+sqr(y-b)+sqr(z-c)>sqr(r1) and
sqr(x-a)+sqr(y-b)+sqr(z-c)<sqr(r2). Can I ask what
how can I select those molecules? Thank you in advance^-^