Most characteristic forms of collectivity in two-dimensional (2D) cellular
structures are the arrangements of non-average cells into anticorrelated ch
ains. The a parameter of 2D Aboav's law can be used for numerical character
isation of collectivity. These concepts are supported by theoretical consid
eration and computer simulation in this paper. (C) 1999 Elsevier Science B.
V. All rights reserved.