5. Linear ionic crystal. Consider a line of 2N ions of alternating charge =q with a repulsive potential energy A/R" betw

[answerhappygod]

5 Linear Ionic Crystal Consider A Line Of 2n Ions Of Alternating Charge Q With A Repulsive Potential Energy A R Betw 1 (78.28 KiB) Viewed 14 times

5. Linear ionic crystal. Consider a line of 2N ions of alternating charge =q with a repulsive potential energy A/R" between nearest neighbors. (a) Show that at the equilibrium separation 2Nq* In 21 (CGS) U(R) ) RO n (b) Let the crystal be compressed so that Ro → Rol1 - 8). Show that the work done in compressing a unit length of the crystal has the leading term C8?, where (CGS) с (n-1)qlo 2 Ro To obtain the results in SI, replace qe by q°/47€). Note: We should not expect to ob- tain this result from the expression for U(Ro), but we must use the complete expres- sion for U(R).