Recent content by pholvey

Just for kicks though, how would you go about working out the derivative of the equation as it is shown in the attachment?

Hey Simon, Ya, I did mean to have symbolic vector derivatives. Unfortunate that Mathematica doesn't know how to handle them...

Hi everyone, Given the attached input and result, I'm confused as to how to interpret the 1.1, x.1, and y.1 terms in the solution. Does this mean I'm supposed to dot 1 into 1? How does that work? Any help is appreciated. Of course, x and y are vectors (not that it matters but they're xyz...

Does anyone have any idea on this? Even showing me how to take the derivative of a dot product summation would be greatly appreciated. Thanks.

Homework Statement This is not a homework problem. I'm trying to do this for research purposes. I have an energy potential (the Keating potential) of the following form (attached). In this form, A, B, and C are force constants, and r_ab is the vector along the bond between atoms a and b...