Show as balls and sticks

import molsysmt as msm
from molsysmt import pyunitwizard as puw
import nglview as nv
import numpy as np

molsys = msm.convert(msm.systems['chicken villin HP35']['chicken_villin_HP35.h5msm'])

view = msm.view(molsys)
view.clear()

msm.thirds.nglview.show_as_balls_and_sticks(view, selection='group_index in [0,1,2]')

view

view = msm.view(molsys)
view.clear()
msm.thirds.nglview.show_as_cartoon(view, selection='all')
msm.thirds.nglview.show_as_balls_and_sticks(view, selection='group_index in [0,1,2]')
view