https://www.ks.uiuc.edu/Research/namd/mailing_list/namd-l.2006-2007/0899.html
namd-l: psfgen: last CTER does not work
does notnamdlcterwork
https://www.ks.uiuc.edu/Research/namd/mailing_list/namd-l.2013-2014/2911.html
namd-l: Re: two O atoms in CTER are unusually close
namdltwo