I am trying ligand protein gromacs tutorial for my protein ligand MD when I come to the command

python cgenff_charmm2gmx.py JZ4 jz4_fix.mol2 jz4.str charmm36-nov2018.ff it says that

This script requires a Python 2.7.x version and the NetworkX package, version 1.11.x - it is incompatible with NetworkX 2.x

When I try to get network it automatically install version that is compatible to the current python that is 2.7.6.

I tried following command

sudo pip install network 1.11.x

it gives following error

Downloading/unpacking network

Downloading network-0.1.tar.gz

Running setup.py (path:/tmp/pip_build_root/network/setup.py) egg_info for package network

Downloading/unpacking 1.11.x

Could not find any downloads that satisfy the requirement 1.11.x

Cleaning up...

No distributions at all found for 1.11.x

Storing debug log for failure in /home/srania/.pip/pip.log

can any body suggest me what to do? I am not familiar with python

Please suggest me

thanks in advance