De. Sanders et al., MECHANISTIC ANALYSIS FROM MOLECULAR-DYNAMICS SIMULATIONS - KEV-PARTICLE-INDUCED DESORPTION FROM SI(001), Physical review. B, Condensed matter, 50(8), 1994, pp. 5358-5369
We have developed a method for interpreting and classifying mechanisms
from molecular-dynamics simulations. The reason for this effort is th
at molecular-dynamics simulations contain a wealth of information rega
rding the microscopic details of atomic motions. It is at best tedious
, however, to extract all of the essential information in very complex
processes. In particular, we are interested in particle ejection due
to the keV-particle bombardment. Our method isolates the motion of the
last two collisions, which we depict in a single frame showing the ti
me sequence of the positions of the three atoms involved. The remainde
r of the atoms are shown at their initial positions. These atoms give
the perspective of the entire system but small or irrelevant displacem
ents do not distract from the key motions. This method is utilized to
elucidate the structure-sensitive mechanisms of keV-particle bombardme
nt of the {001} face of diamond-lattice crystals. We have observed tha
t two mechanisms are responsible for the major features of the angular
distributions, namely, the DELTA1 and the DELTA3 mechanisms. The two
mechanisms are characterized by the difference in the number of layers
of the atoms involved in the final momentum transfer.