[Smeagol-discuss] Total Energy

[Simon Dubois]

Dear Smeagol Users and Developpers,

I have some questions related to the computation of the total energy in
Siesta and Smeagol.

(a) I know that, due to the presence of the self-energies, the effective
SCF hamiltonian computed within smeagol is no more hermitian and that the
eigenenergies are thus complex number. However, if I am not mistaking, the
real part of these complex number still have the meaning of an energy
while the complex part is related to the quasi-particle lifetime. Is that
true ?

(b) If the previous point is true, then, in order to compute the total
energy of the open boundary system, we should simply add a term
E_self = trace([rho]*[self_L + self_R])
to the total energy computed by Siesta.

(c) I have noticed the following differences between the enregy terms
computed by Smeagol (left side) and Siesta (right side):

siesta:-Eions   = -167171.565970       167171.565970
siesta: Ena     =   14152.066946        14152.066948
siesta: Ekin    =   82725.940493        82743.197427
siesta: Enl     =  -29606.795074       -29621.564038
siesta: DEna    =    1570.039623         1561.672622
siesta: DUscf   =      73.434271           72.756367
siesta: DUext   =       0.000000            0.000000
siesta: Exc     =  -19114.634221       -19118.273918
siesta: eta*DQ  =       0.000000            0.000000
siesta: Emadel  =       0.000000            0.000000
siesta: Ekinion =       0.000000            0.000000
siesta: Eharris = -117371.513978      -117381.709241
siesta: Etot    = -117371.513933      -117381.710563
siesta: FreeEng = -117371.513933      -117381.742383

Is it the NEGF density matrix which is used to compute these energies
within Smeagol ? In this case, do these differences simply originate in
the modification of the electronic density due to the presence of the
self-energies?

Any comments are welcome..... Thanks in advance!

Best wishes,

Simon

-- 
Simon Dubois

PhD Student
Ecole Polytechnique de Louvain
Unité de Physico-Chimie et de Physique des Matériaux (PCPM)
Place Croix du Sud, 1
B-1348 Louvain-La-Neuve (Belgium)
Tel. 010/47.28.38