group — A generic group of one datatype or one kind.
group ::= (parameter*,attrib*)
The group element contains the properties of a group identified by a name and the attributes of the group.
Add the number of elements in a group to the parent node.
Required, the name of the group, e.g., species.
Optional, the number of elements in this group. Default is 0.
Optional, a supergroup to which this group beongs to. Default is "none".
Optional, the constraint on the group. "random" is used in QMC to generate random positions for the number of elements in the group.
Reserved to refine the group.
Example 3. Using group element in particleset.
The group element is used to create a cubic InAs Zincblende structure excluding unitcell declaration.
<particleset>
<group name="In" size="4">
<parameter name="mass" condition="amu">114.919</parameter>
<attrib name="position" datatype="posArray" condition="1">
0.0 0.0 0.0
0.5 0.5 0.0
0.0 0.5 0.5
0.5 0.0 0.5
</attrib>
</group>
<group name="As" size="4">
<parameter name="mass" condition="amu">74.92160</parameter>
<attrib name="position" datatype="posArray" condition="1">
0.25 0.25 0.25
0.75 0.75 0.25
0.25 0.75 0.75
0.75 0.25 0.75
</attrib>
</group>
</particleset>