[Pw_forum] DFT+U: about how to get U

[Chao Cao]

Hi there,
  I read about M. Cococcioni's paper and thesis on how to get the U
parameter, and have the following question on mind:
  Does the procedure of perturbing atomic occupation go through every
single atom or just "hubbard" atoms? In the latter case, does the
response matrix chi include elements related with hubbard atoms only (
i.e. chi(m,n) m and n are both hubbard atoms ), or it has to include
everything? If it includes everything, what do we do about elements
related to non-hubbard atoms (maybe set them to 0 (?))?

  Thanks in advance.

Chao Cao

-- 
Chao Cao

Quantum Theory Project and Department of Physics
University of Florida, Gainesville, FL 32611
U.S.A.