After I run ‘emc_setup.pl polymer’, it gives one warning:‘field ‘pcff’ not found; no changes’ and opls-ua is used. I am wondering how I can correctly apply the PCFF force field to build a polymer.
The easiest way to fix this problem is to set the environment variable EMC_ROOT. When you are using LINUX, you can set this variable by
export EMC_ROOT=/your/emc/version
You can make this your default by permanently adding the above to your ~/.bashrc. See ‘How to setup EMC for Windows’ for setting environment variables under Windows.
Thanks for the reply! Actually I have already set the environment variables according to the link you posted (please see screenshots below) before I tried running the script.