[Getdp] Quantum Mechanics in GetDP

Tony Harker a.harker at ucl.ac.uk
Wed Jul 25 12:44:43 CEST 2007


 I'm new to GetDP, and am trying to use it to solve a problem in quantum
mechanics (an electron confined in a geometrically complicated potential
well). I have a couple of problems, though:
 1. If I recover the eigenvalues using Format TimeTable what I get is the
result of the solver assuming that the eigenvalues were squares of angular
frequencies, which are converted to angular frequencies for TimeTable. What
I really need is the original square, corresponding to the energy.
Alternatively, I could recover it if I knew how to get TimeTable to return
both the real and imaginary parts of the 'time' (i.e. angular frequency): is
this possible?
 2. I seem to be having problems getting Arpack to converge onto the
algebraically smallest eigenvalue. Has anybody any tips for the best use of
Arpack within GetDP?

 I should add that I've experimented with some simpler wave-in-a-box
problems and got exactly the results I expected.

    Tony

Dr A.H. Harker
Department of Physics and Astronomy
University College London
Gower Street
London
WC1E 6BT

Tel: (44)(0) 2076793404
E:    a.harker at ucl.ac.uk