Dear Quantumwisestaffs:
Recently i decided to calculate heterojunctions, i learned from post
http://quantumwise.com/forum/index.php?topic=4038.msg18443#msg18443that the
NeutralAtoms option should be used for the heterogeneous system, but what confused me most is that the phrase in the Atomistix ToolKit Reference Manual"
Length over which the atoms in the electrode copy within the central region will be initialized with a linear combination of the converged density matrix of the electrodes and the equivalent bulk density matrix. The weight of the electrode density matrix is 1 at the boundary and 0 at the distance electrode_constraint length from the boundary"from
http://www.quantumwise.com/documents/manuals/ATK-2015/ReferenceManual/index.html/ref.neutralatom.html.
The question is that since the equivalent bulk is replaced by NeutralAtoms for heterojunctions, why the equivalent bulk calculation is still involved to get the equivalent bulk density matrix before the first device electronic convergence. On the other hand, how should we pick appropriate
electrode_constraint _length for NeutralAtoms option, or how the magnitude of
electrode_constraint_length influence the speed for the subsequent device eletronic convergence. for example, convergence speed will be accelerated if we use the electrode length in the Z direction or just set zero value for
electrode_constraint_length?
