Thanks for kind advices. Whatif and PISA worked excellently, but I want to get the list within Pymol.
By parsing the pymol modules, I found hb = cmd.find_pairs("((byres "+sss1+") and n;n)", "((byres "+sss1+") and n;o)",mode=1, cutoff=3.7,angle=55, state1=state,state2=state) in util.py. Is it possible to get a list of main-chain hydrogen bonds with this function? Any suggestions and advices are welcomed. Thanks in advance. Tomoko