Register to reply

Madelung constant

by Petar Mali
Tags: constant, madelung
Share this thread:
Petar Mali
#1
Apr3-10, 07:35 AM
P: 290
1. The problem statement, all variables and given/known data
Applying the method of Evjen calculate Madelungovu constant of infinitely long series of alternately opposite charged ions. Show that summarize by the Evjen cells gives the value Madelung constant [tex]A_n[/tex] whose deviation from actual value [tex]A[/tex] is less than [tex]\frac{1}{n^2}[/tex]


2. Relevant equations
Madelung constant Madelung constant for the infinite number of ions alternately changing signs

[tex]A=2(1-\frac{1}{2}+\frac{1}{3}-\frac{1}{4}+...)=2ln2[/tex]



3. The attempt at a solution
Evjen method is method in which we look in neutral structures. So I think that first neutral structure is one whole ion and two neighbours cut in half. And second neutral structure is all other ions. Is it than Madelung constant for first neutral structure

[tex](A)_I=2\cdot 0,5=1[/tex]

and for second neutral structure

[tex](A)_{II}=2(0,5-\frac{1}{2}+\frac{1}{3}-...)[/tex]

And

[tex]A_n=(A)_I+(A)_{II}[/tex]

But where I have [tex]n[/tex] in here?
1. The problem statement, all variables and given/known data



2. Relevant equations



3. The attempt at a solution
Phys.Org News Partner Science news on Phys.org
Hoverbike drone project for air transport takes off
Earlier Stone Age artifacts found in Northern Cape of South Africa
Study reveals new characteristics of complex oxide surfaces
Petar Mali
#2
Apr5-10, 07:56 AM
P: 290
Any idea?


Register to reply

Related Discussions
Madelung constant Atomic, Solid State, Comp. Physics 1
Madelung constant Atomic, Solid State, Comp. Physics 1
The Madelung energy/constant?! Advanced Physics Homework 0
Constant volume versus constant pressure batch reactor Engineering, Comp Sci, & Technology Homework 0
Constant power delivered to coil, constant magnetic field? Electrical Engineering 0