Ground-state structures of polymers

Two- and three-dimensional structures A(x)B(y) can be characterized by the numbers T-1 and T-2 of nearest and next-nearest neighbors of the same kind. A small number of structures at the border of the T-1, T-2 structure map i s stabilized by enthalpy compared to an increased number of entropy stabili zed structures. About 60 three-dimensional structures with T-1 = 2 nearest neighbors of all A atoms are suitable for infinite chains of polymers like (CH)(infinity), (CHCH2)(infinity), or (CH2)(infinity). (C) 2001 John Wiley & Sons, Inc.