Example of topology for butane molecule

topol.xml

<topology>
    <h5md_particle_group name="atoms" />
    <molecules>
        <molecule name="BUT" nmols="4000" nbeads="4">
            <bead name="C1" type="C" mass="15.035" q="0.0" />
            <bead name="C2" type="C" mass="14.028" q="0.0" />
            <bead name="C3" type="C" mass="14.028" q="0.0" />
            <bead name="C4" type="C" mass="15.035" q="0.0" />
        </molecule>
    </molecules>
    <bonded>
        <bond>
            <name>bond1</name>
            <beads>
                BUT:C1 BUT:C2
            </beads>
        </bond>
        <bond>
            <name>bond2</name>
            <beads>
                BUT:C2 BUT:C3
            </beads>
        </bond>
        <angle>
            <name>angle1</name>
            <beads>
                BUT:C1 BUT:C2 BUT:C3
                BUT:C2 BUT:C3 BUT:C4
            </beads>
        </angle>
        <dihedral>
            <name>dihedral1</name>
            <beads>
                BUT:C1 BUT:C2 BUT:C3 BUT:C4
            </beads>
        </dihedral>
    </bonded>
</topology>