I have a question about the input for the two body terms of the Stillinger-Weber potential (sw2) in GULP. Let’ say, we have a system with two atom types: Si and O for example. Now, we know the two body-terms for Si-O and O-Si interactions should be same as they are the same bonds.
My question is:
Should I enlist both Si-O and O-Si interactions in the input file, albeit them being of equal value? Or should I just list one of them only (either Si-O or O-Si interaction)?
Thanks and please let me know if you have any sugeestions.
Shoieb Ahmed CHowdhury