compute the fragment centroid
| Type | Intent | Optional | Attributes | Name | ||
|---|---|---|---|---|---|---|
| class(fragment_type), | intent(in) | :: | this | 
pure function fragment_centroid(this) result(centroid)
    class(fragment_type), intent(in) :: this
    real(dp), dimension(3) :: centroid
    centroid = compute_centroid(this%atoms)
end function fragment_centroid