Ab initio calculations on the dissociative reaction of As4 molecules

The dissociation of an As4 molecule in vacuum was studied. At first, we calculated the energy for the dissociation of one As4 molecule without the restriction of symmetry and it is found that the energy barrier of the reaction path is smaller than that reported previously. Next, we calculated the dissociation of an As4molecule under interaction with another As4 molecule and found that this energy barrier is smaller than that of the former. This means that at high As4pressure, two As4 molecules react and give As2 molecules which agrees with the model given by Foxon and Joyce in molecular beam epitaxy MBE.of GaAs. q2000 Elsevier Science B.V. All rights reserved