Assignment 1

 

1. What is the connection between electronic charge density distribution and the molecular structure hypothesis? What are the theoretical and experimental sources for charge density? (Not more than 2 pages!)

 

2. In a crude model for chemical binding, an electron each is trapped in two potential wells with infinite walls and width a/2. Their reaction to form a bond is represented as merger of the two wells to form a single well of width a units. Calculate the “binding energy” in units of h2/ma2 for the following cases:

 (a) V = 0 inside both boxes.

(b) V= 0 inside one box, and V= v in the other box, such that v << 1 (in units of h2/ma2).

(c) As in (b) but v >> 1.

What is the main cause of bonding (reduction of kinetic or potential energy)?

 

3. The expressions for the overlap integral, coulomb integral, and resonance integral for the hydrogen molecule ion are given in Levine, p. 359-360. Assuming a value of 1.0 for the orbital exponent, plot these three integrals as well as the product of overlap and coulomb integrals on the same graph for internuclear distance ranging from 0 to 5 a.u. What do you observe?

 

Assignments should be written neatly on A4 size paper only. The first page should contain only name (yours, NOT MINE) and roll number. The sheets should be tied or pinned together on the left hand top corner. Don’t do any further binding and don’t submit in folders.

Be Original!