QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: hzkvictory on March 31, 2013, 06:32
-
Local Device Density of States is avialable in device_configuartion.
But when it comes to molecule_configuration and bulk_configuration, LDOS is not acessible.
how to get the LDOS (the partical charge density at fixed energy)of a single molecule ?
-
Please see the discussion in the following page:
http://quantumwise.com/forum/index.php?topic=2203.0
AB provided a script to get the \psi^2 of a given eigenstate.
-
your resolution is ok for bulk_configuration.
but for molecule_configuration, "BlochState()" is not available, how to deal with it ?
-
I have an idea, but some problems stuck in front.
In my opinion, the "eigenstate" of molecule is similar to "bloch state" of bulk system,
So LDOS can be obtained by sum the eigenstates of specific quantum numbers,
because we LDOS of particular energy range,
energy spectrum of molecule should first be calculated, in this way, we can find out the detailed quantum numbers distributed among the particular energy range.
then, sum the eigenstates together.
However, there are some doubts:
1. eigenstate is described in red and blue, indicating phase of wavefunction. But what is the related physics ?
2. can eigenstated be sumed ?
3. In fact, I would like to be surel, wether LDOS is the electron density of particular energy range, and wether eigenstate of molecule is the electron density of a specific quantum number.
-
Yes, eigenstate (psi) is the molecule counterpart of a bloch state,
LDOS is the sum of |psi_n|^2 f(e_n) where f is the fermi function
-
1. The eigenstate is a complex function, hence when we plot it the data for the contour or isosurface is the magnitude (|psi|^2) and the phase determines the coloring.
2. See http://quantumwise.com/forum/index.php?topic=2203
3. See above.