Hi, I’m very new to Gulp and am trying to run some simulations on W and WC, employing the Tersoff potential. I had a look at the help doc of this package to insert the parameters required i.e.:
boonebody
: atom1 alphaA alphaB nA nB
botwobody
: atom1 atom2 A B za zb rtaper rmax
borepulsive
: atom1 <omega_ik> lambda
boattractive theta
: atom1 <omega_ik> lambda c d h
By comparison between the equation used in the Gulp and the one provided by Juslin et al. (Journal of applied physics 98, 123520 (2005)), I considered za = λ and zb =µ.
Now I have these questions:
1: What are rtaper and rmax exactly? In example 77 they are in fact the values of R and S respectively, reported by Munetoh et al (Comp. Mat. Sci., 39, 334 (2007)), but in example 28 they don’t match with the values of R and S reported for Si. In this example rmax=cutd which makes sense but not sure how the value of rtaper is set here.
2: What does lambda exactly stand for in borepulsive and boattractive theta? I was expecting to have the value of λ in the repulsive term and the value of µ in the attractive term for this flag, but in example 28, it’s got the value of µ for both borepulsive and boattractive theta and in example 77, it’s got a zero value for both borepulsive and boattractive theta.
Any advice is highly appreciated!!!
Regards,