I am curious what tree names S, B, 3, E stand for in Group
Specification.
These are topological types. From the prep doc:
Any atom that is not a main atom is described by one of
the other topological types: "E", "S", "B", "3", "4", "5", or
"6". An "E" atom has only one connection to other atoms, thus
is a "dead end" for any branch from any other atom type. An
"S" atom must have a total of two connections to other atoms,
a "B" atom must have a total of three connections, and a "3"
atom actually has a total of four connections; the same applies
for "4" "5" and "6".
Bill Ross
Received on Thu May 10 2001 - 18:37:01 PDT
