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symbolic calculation in quantum mechanics

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ptc-4495199
Newbie

symbolic calculation in quantum mechanics

Hello all,

I want to reproduce with Mathcad some symbolic quantum mechanics calculations done with Mathematica.

It is just standard homework question.

Occasionally, the correct formal equation just stall.

It is a lost cause or does it some special syntax I am not aware of ?

I am using Mathcad 15.

Thanks for the help,

Pierre

1 ACCEPTED SOLUTION

Accepted Solutions

Re: symbolic calculation in quantum mechanics

I chanced upon this today, and wondered if you were pursuing the inner product, not the sum of the elements squared...note the assignment of a symbolic result to a variable...The latest Mathematica has more support for QM symbolics, but overall it seems that it will not quite do as much for me as Mathcad, though my work is more "concrete", even when addressing theoretical physics questions.

quantum+mechanics+vector+inner+product.gif

View solution in original post

8 REPLIES 8

Re: symbolic calculation in quantum mechanics

These integrals are too difficult for the Mupad symbolic engine in M15 to deal with. Since Hermite polynomials have a simple recurrence relationship it's possible the approach illustrated below might be of some use to you.

Alan

Hermite.PNG

Re: symbolic calculation in quantum mechanics

Great answer

Re: symbolic calculation in quantum mechanics

Hi,

I have got a strange result.

The sum of squared matrix elements gives "55" where it should show just "5".

When I check the elements individually, it shows that the sum should be 5 !

What happened ?

Thanks for the help,

Pierre

8-p22squared.jpg

Re: symbolic calculation in quantum mechanics

If you don't vectorize, the product of two vectors is a scalar: the dot product.

Also, you can't sum over the range of n=0 to 10, because n does not appear as an index in the expression. Just use a vector sum.

dot+product.jpg

Re: symbolic calculation in quantum mechanics

It looks better.

Thanks again,

Pierre

Re: symbolic calculation in quantum mechanics

I chanced upon this today, and wondered if you were pursuing the inner product, not the sum of the elements squared...note the assignment of a symbolic result to a variable...The latest Mathematica has more support for QM symbolics, but overall it seems that it will not quite do as much for me as Mathcad, though my work is more "concrete", even when addressing theoretical physics questions.

quantum+mechanics+vector+inner+product.gif

View solution in original post

Re: symbolic calculation in quantum mechanics

Hi Rich,

Thanks for the feedback.

Sorry for the late reply.

I did not have a chance to do symbolic QM calculation since the last semester.

But it looks like you provided the right path.

Note that with my notation, hb stands for h barr (h.b is a misunderstanding of the notation).

Thanks again,

Pierre

Re: symbolic calculation in quantum mechanics

Hi Allan,

It looks great.

Thanks,

Pierre

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