Group Abstract Group Abstract

Message Boards Message Boards

Getting Wrong Numbers in Output for a Quantum Mechanics problem

خالد رافع
Posted 2 years ago

I am a noob in Mathematica. I am trying to solve a Quantum Mechanical problem of particle in a one-dimensional box. The program was written for Mathematica 6. But, I ran it in Mathematica 14. The expected output in second to fifth output was like below: 

Out[45]= 14.0353
Out[46]= 55.7956
Out[47]= 124.253
Out[48]= 217.721
Out[49]= 333.898

But instead, it shows this:

Out[45]= -4621.58
Out[46]= -1231.51
Out[47]= -869.209
Out[48]= -504.838
Out[49]= -385.284

See below.

What could be causing this? And how to solve the issue?
POSTED BY: خالد رافع
6 Replies
Sort By:

How to run programs written for Mathematica 6 in Mathematica 14? Some programs show a different output than expected in Mathematica 14. For example, look at the attached notebook

The program gives this output below the matrix in Mathematica 6:

14.0353
55.7956
124.253
217.721
333.898
14.0642
56.2568
126.578
225.027
351.605

But in Mathematica 14, the ouput below the matrix is:

-4621.58 
-1231.51 
-869.209 
-504.838 
-385.284 
14.0642
56.2568
126.578
225.027
351.605

How can I get the same output as Mathematica 6 in Mathematica 14? What settings should I change? Is there any compatibility setting available?

Turns out the issue is a version issue. The program shows a different output in Mathematica 14 than in Mathematica 6. How to solve this?
POSTED BY: خالد رافع

Here is a way:

{E1, E2, E3, E4, E5} = X/(16/10*10^-22) /. B[[1 ;; 5]];
TableForm[{{E1, E2, E3, E4, E5},
   {E1, E2, E3, E4, E5} // N,
   {E1exact, E2exact, E3exact, E4exact, E5exact}} //
  Transpose,
 TableHeadings -> {None, 
   {"E symbolic", "E numeric", "Exact"}}]
POSTED BY: Gianluca Gorni

I would do as much of the calculation in exact arithmetic as possible:

a = 20*10^-9;
h = a/20;
m = Rationalize[0.067*9.1]*10^-31;
hcutsq = ((Rationalize[6.626]*10^-34)/(2*Pi))^2;

This way the numbers turn out quite different. I have no idea if they are still weird.
POSTED BY: Gianluca Gorni

Sorry, there was a mistake in the question. The expected output in second to fifth output is below:

Out[45]= 14.0353
Out[46]= 55.7956
Out[47]= 124.253
Out[48]= 217.721
Out[49]= 333.898

But instead, it shows this:

Out[45]= -4621.58
Out[46]= -1231.51
Out[47]= -869.209
Out[48]= -504.838
Out[49]= -385.284
POSTED BY: خالد رافع
Reply to this discussion
Community posts can be styled and formatted using the Markdown syntax.
Tag limit exceeded
Note: Only the first five people you tag will receive an email notification; the other tagged names will appear as links to their profiles.
Reply Preview
Attachments
Remove
or Discard
Be respectful. Review our Community Guidelines to understand your role and responsibilities. Community Terms of Use