To the moderator: I'm not sure if this should go here or in the Computational Physics forum. Please shift it there if you think thats the appropriate place for it.(adsbygoogle = window.adsbygoogle || []).push({});

Hi everyone

Merry Christmas!

I'm writing a computer program in C, to explicitly compute the band structures for a 1D crystal modelled as an infinite array of rectangular potential barriers of width 2a and distance between nearest walls of two successive barriers 2b, i.e. the Kronig Penney Model.

My program correctly plots the energy versus (normalized) wavenumber graph in the extended wavenumber scheme, but when I try to superimpose the free particle parabola on this graph (i.e. the parabolic graph of energy versus wavenumber for a free particle), it is not found to intersect the band curves at points of the form [itex]n\pi[/itex] where [itex]n[/itex] is an integer. (I call gnuplot from within my C program to plot this curve.)

The plot generated by the program is as shown in the attachment.

I think this is because of some numerical approximations and propagation errors, but I haven't been able to fix it. As you can see from the plot, the two curves do intersect at [itex]\pi[/itex] (or very nearly so) but thats just it.

I would appreciate any ideas or suggestions. I can post my algorithm/code here if you wish.

Thanks in advance,

Cheers

Vivek.

**Physics Forums - The Fusion of Science and Community**

Join Physics Forums Today!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

# Problem plotting Kronig Penney Model dispersion curves

Loading...

Similar Threads - Problem plotting Kronig | Date |
---|---|

I Born Oppenheimer problem | Oct 4, 2017 |

A Warren X-ray difrraction solutions manual | May 22, 2017 |

A Problem in continuous function of Excimer laser | Aug 30, 2016 |

B Finite difference problem | May 16, 2016 |

How to make contour plots for 2D Finite Element problems | Sep 3, 2009 |

**Physics Forums - The Fusion of Science and Community**