1.) Are there major differences between 11.2.b2 and 11.2.0 / 11.2.r1?
There are certainly a few differences, including several crucial bug fixes of problems in the b2 version. Moreover, you cannot use the b2 version beyond 1 April, it will simply not work any more.
2.) At the beginning of the transmission spectrum calculation, I got the following error:
** Back Engine Exception 92 : Too large a difference in calculated transmissions has been detected among processes
** Location : calculatetransmissioncoefficient.cpp:166
What could be the reason?
I have to mention that the device density matrix calculation did not converge and there were large difference density values on some atoms.
For instance, this is fixed in 11.2.0
3.) As I'm often dealing with long metallic systems I am curious about the new Kerker preconditioner. The documentation there is a bit confusing to me. In the explanation of energy_q0 what do you mean with "i.e 0.5*q0*q0" ? Or "energyQ0(): Return 0.5*q0*q0". Is enegry_q0 equal to q0 or is energy_q0 equal to 0.5*q0*q0 ?
I agree it's a bit cryptic
The algorithm uses q0, which is an inverse length. If you compute E=hbar^2 q0^2 / 2m, this will have the dimension of energy. In atomic units, hbar and the electron mass m are both 1, so we can compute q0 from E=0.5*q0*q0. The input to Kerker is energy_q0=E, and from this we can compute q0 internally.
4.) Some things about the ReferenceManual: In the DeviceCalculator sections there is no hint about the new FFT2D solver. On some pages (e.g. 97, 98, 101, ...) in the new Manual there is lots of red text that looks as it should be formatted in a different way.
From a formal perspective, the Poisson solver is completely uncoupled from the geometry; you can run the same geometry with many different boundary conditions. We also do not discuss the other Poisson solvers on this page. So I don't think it's an appropriate place for it, although there is a general need for a more detailed discussion on the two-probe geometry, which partly is available here:
http://quantumwise.com/publications/tutorials/mini-tutorials/99The red things should be fixed - we'll look into it, thanks!
