I have a wired problem with angles in the lammps data file.
For example, if I have a water molecule, then the angles should be
1 1 1 3 2. (HHO,atomID is 1,2,3.)
Then I add an oxygen molecule under the water, the angles should be
1 1 1 2 3
2 2 4 5.(O2,atomID is 4,5.)
It worked well.
it may have run, but it is incorrect. there is no angle in a diatomic and
you switched the order of the atoms for the water molecule.
adding an angle definition by itself doesn't do anything unless you also
change the number of angles in the header. *had* you done that, you would
get the same error as given below.
But when I have a system with pure oxygen, it always failed with the
message invalid atomID in angles section.
I read from manual that the syntax for angles is ID type atom1 atom2
So does it mean that when I write angles in data file, there must be
three atoms in an angle?
But if it is, why my water and oxygen data worked well surprisingly?
I know an angle for a two-atom molecule is 180 degree. I tried to
delete the angles of oxygen in data file and it also didn't work.
this is complete nonsense. an angle potential requires 3 atoms.