Wurtzite (W)-zinc blende (ZB) structural stability of semiconductors is systematically investigated based on a newly developed empirical potential, which incorporates electrostatic energies due to bond charges and ionic charges. Using the empirical potential, the system energies are calculated for bulk and various heterostructures such as GaN(0 0 0 1)/ GaAs(1 1 1) and GaN(0 0 0 1)/AlAs(1 1 1). The calculated results predict that W-structured GaN is more stable on AlAs(1 1 1) compared to that on GaAs(1 1 1). The W-ZB structural stability is discussed in terms of strain energy and electrostatic energy contributions. The calculated results imply that ionicity difference between thin film and substrate materials is crucial for understanding the W-ZB structural stability in heterostructures consisting of (0 0 0 1)-oriented W-structured and (1 1 1)-oriented ZB-structured semiconductors. (C) 2002 Elsevier Science B.V. All rights reserved.