# EXAMPLE 2
# Show hydrogen bonds between two proteins

load prot1.pdb
load prot2.pdb

h_add prot1
h_add prot2

select don, (elem n,o and (neighbor hydro))
select acc, (elem o or (elem n and not (neighbor hydro)))
dist HBA, (prot1 and acc),(prot2 and don), 3.2
dist HBD, (prot1 and don),(prot2 and acc), 3.2
delete don
delete acc
hide (hydro)

hide labels,HBA
hide labels,HBD

# NOTE: that you could also use this approach between two
# non-overlapping selections within a single object.