The meaure command supplies several algorithms for analyzing molecular structures. In the following options, selection refers to an atom selection, as returned by the atomselect command described in section 8.3.2. The optional weight must be either none, an atom selection keyword such as mass, or a list of values, one for each atom in the selection, to be used as weights. If weight is missing or is none, then all weights are taken to be 1. When an atom selection keyword is used, the weights are taken from selection1.
Known Issue: The output of hbonds cannot be considered 100% accurate if the donor and acceptor selection share a common set of atoms.