How can I solve for the x force component in this force expression?

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Jorzef
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Homework Statement
Derive the expression to the x force component exerted by an oxygen atom of a molecule j over the oxygen atom of a i molecule knowing that the force expression is given by (equation on attempt at a solution)
Relevant Equations
Equations on attempt at a solution
Typed problem statement with equations: force between oxygen atoms F_ij = -(1/r_ij)[d/dr_ij U(r_ij)] r_ij, U = U_vdw + U_coul, Lennard-Jones and Coulomb double-sum potentials.


Hello everyone, I'm stuck doing this problem, I've tackled the partial derivative but i can't figure out the derive for x component part, i solved the partial derivative part, i came to this result:
Handwritten force expression: minus a bracket containing 4 epsilon-zero times (minus 12 sigma-zero-zero to the 12th over r_ij to the 14th, plus 6 sigma-zero-zero to the 6th over r_ij to the 8th), minus 1 over 4 pi epsilon-zero times d_i d_j over r_ij cubed, all multiplied by vector r_ij.

What do can i do from here on, thank you!
 
Jorzef said:
Homework Statement:: Derive the expression to the x force component exerted by an oxygen atom of a molecule j over the oxygen atom of a i molecule knowing that the force expression is given by (equation on attempt at a solution)
Relevant Equations:: Equations on attempt at a solution

View attachment 262781

Hello everyone, I'm stuck doing this problem, I've tackled the partial derivative but i can't figure out the derive for x component part, i solved the partial derivative part, i came to this result:
View attachment 262782
What do can i do from here on, thank you!
"Derive" has two meanings in mathematics. It can mean the differential calculus operation of taking a derivative, or it can simply mean to obtain one equation from others by algebraic means.
I have the feeling you have applied the wrong one.