|From:||Ray Shan <rshan@...1795...>|
|Date:||Wed, 9 May 2018 21:14:32 +0000|
This doesn’t matter. In Tersoff potential files a trio (A B C) means the bonding of B—A—C, which in many cases (e.g., Si Si C) have BA or AC bond lengths beyond the cutoff for the compound it parameterized for (SiC in this case). Therefore it doesn’t matter if parameters like A, B, lambda, etc are zeros or not, since Si-Si-C bonds do not exist. For your own potential file you need to determine if such bonds exist or not, but just make them non-zeros to be on the safe side.
I have a very serious problem on building a correct data file for Tersoff potential. Suppose that I want to build it for a system of two type atom, i.e. A and B. It is obvious that data for ( A A A ) and ( B B B ) rows are available in paper. But, how about other 6 rows of data ? I mean ( A A B ) , ... (B B A ). I tried to understand the logic behind it. But, for example in SiC so many parameters are equal with 0. However, when I go through BNC m and check for example ( B B C ), zeros terms are not in agreement with ( Si Si C ) for example. Any comment please ?