Hi List,
I am trying to do simulations with a mixture of two SW atom types. The documentation of cdte.sw
(Stillinger-Weber parameter file for a two type system) says that two body parameters are *not* read
from the i-j-i and i-i-j terms, and sets those to zero for simplicity.
Nevertheless, i find that the results of a single point calculation *change* when the zeros are replaced
by numbers... So the program is actually reading and using these two body parameters.
Does someone know how is the program assigning the parameters is reading?
(e.g. in i-j-j, is using them for i-j or j-j?)
Below are the details of my results.
thanks for your help,
Vale
Results: I made a SiGe parameter file with all lines the same (bottom) and then change sigma from 2.3925 to 4.3925 one line at a time:
step temp pe etotal press pxx pyy pzz PARAMETERS
0 268.21782 -4315.5918 -4073.3414 15898.249 9045.1781 20493.841 18155.726 all 8 lines same param
0 268.21782 160369.86 160612.11 2478168.6 2355438.3 2667115.8 2411951.7 change sigma in line 1 Si Si Si
0 268.21782 22944.409 23186.659 583672.71 549561.95 548732.29 652723.89 change sigma in line 2 Si Si Ge
0 268.21782 28140.453 28382.703 149328.57 189121.25 173669.94 85194.527 change sigma in line 3 Si Ge Si
0 268.21782 20303.848 20546.098 292069.72 210980.24 313758 351470.92 change sigma in line 4 Si Ge Ge
0 268.21782 23748.895 23991.145 400628.06 356218.3 446486.57 399179.3 change sigma in line 5 Ge Si Si
0 268.21782 21134.528 21376.778 531210.78 508332.05 476233.25 609067.02 change sigma in line 6 Ge Si Ge
0 268.21782 25733.33 25975.58 57696.499 -27746.824 146542.38 54293.938 change sigma in line 7 Ge Ge Si
0 268.21782 240316.69 240558.94 2708562.2 2467874.3 2831311.3 2826501.1 change sigma in line 8 Ge Ge Ge
The original made-up parameter file has all lines identical:
Si Si Si 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Si Si Ge 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Si Ge Si 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Si Ge Ge 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Ge Si Si 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Ge Si Ge 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Ge Ge Si 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0
Ge Ge Ge 6.45 2.3925 1.80 23.3 1.20 -0.333333333333 7.049556277 0.6022245584 4.0 0.0