Yambo Community Forum

Dear Users,

I am trying to calculate the Electric Field enhancement in a system with plasmons. Therefore, I need to compare the magnitude of the electric field of light with the electric field of induced charge density. I can calculate the induced charge density and the magnitude of the electric field created by that but how am i supposed to calculate the magnitude of the electric field of light and what its units would be (I need the comparison with SI units)? The only input in my yambo.in file is;

% LongDrXd
1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field

Thanks in advance,

Cheers,

sener

PS: Here is the whole yambo.in input file;

optics # [R OPT] Optics
chi # [R CHI] Dyson equation for Chi.
rim_cut # [R RIM CUT] Coulomb potential
StdoHash= 20 # [IO] Live-timing Hashes
Nelectro= 43.00000 # Electrons number
ElecTemp= 0.000000 eV # Electronic Temperature
BoseTemp=-1.000000 eV # Bosonic Temperature
OccTresh=0.1000E-4 # Occupation treshold (metallic bands)
NLogCPUs=0 # [PARALLEL] Live-timing CPU`s (0 for all)
DBsIOoff= "none" # [IO] Space-separated list of DB with NO I/O. DB=(DIP,X,HF,COLLs,J,GF,CARRIER
s,W,SC,BS,ALL)
DBsFRAGpm= "none" # [IO] Space-separated list of +DB to be FRAG and -DB NOT to be FRAG. DB=(DIP,
X,W,HF,COLLS,K,BS,QINDX,
FFTGvecs= 10000 RL # [FFT] Plane-waves
#WFbuffIO # [IO] Wave-functions buffered I/O
X_q_0_CPU= "" # [PARALLEL] CPUs for each role
X_q_0_ROLEs= "" # [PARALLEL] CPUs roles (k,c,v)
X_q_0_nCPU_invert=0 # [PARALLEL] CPUs for matrix inversion
X_finite_q_CPU= "" # [PARALLEL] CPUs for each role
X_finite_q_ROLEs= "" # [PARALLEL] CPUs roles (q,k,c,v)
X_finite_q_nCPU_invert=0 # [PARALLEL] CPUs for matrix inversion
X_Threads= 8 # [OPENMP/X] Number of threads for response functions
DIP_Threads= 8 # [OPENMP/X] Number of threads for dipoles
NonPDirs= "none" # [X/BSS] Non periodic chartesian directions (X,Y,Z,XY...)
RandQpts=1000000 # [RIM] Number of random q-points in the BZ
RandGvec= 7 RL # [RIM] Coulomb interaction RS components
#QpgFull # [F RIM] Coulomb interaction: Full matrix
% Em1Anys
0.00 | 0.00 | 0.00 | # [RIM] X Y Z Static Inverse dielectric matrix
%
IDEm1Ref=0 # [RIM] Dielectric matrix reference component 1(x)/2(y)/3(z)
CUTGeo= "box z" # [CUT] Coulomb Cutoff geometry: box/cylinder/sphere X/Y/Z/XY..
% CUTBox
0.00 | 0.00 | 75.61 | # [CUT] [au] Box sides
%
CUTRadius= 0.000000 # [CUT] [au] Sphere/Cylinder radius
CUTCylLen= 0.000000 # [CUT] [au] Cylinder length
#CUTCol_test # [CUT] Perform a cutoff test in R-space
Chimod= "Hartree" # [X] IP/Hartree/ALDA/LRC/BSfxc
NGsBlkXd= 500 RL # [Xd] Response block size
% QpntsRXd
3 | 3 | # [Xd] Transferred momenta
%
% BndsRnXd
10 | 50 | # [Xd] Polarization function bands
%
GrFnTpXd= "c" # [Xd] Green`s function t/c/r/a
% EnRngeXd
-5.00000 | 5.00000 | eV # [Xd] Energy range
%
% DmRngeXd
0.05000 | 0.05000 | eV # [Xd] Damping range
%
DmERefXd= 0.000000 eV # [Xd] Damping reference energy
CGrdSpXd= 100.0000 # [Xd] [o/o] Coarse grid controller
ETStpsXd= 400 # [Xd] Total Energy steps
EMStpsXd= 100.0000 # [Xd] [o/o] Memory Energy steps
DrudeWXd= ( 0.00 , 0.00 ) eV # [Xd] Drude plasmon
% EhEngyXd
-1.000000 |-1.000000 | eV # [Xd] Electron-hole energy range
%
% LongDrXd
1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field
%
XfnQPdb= "none" # [EXTQP Xd] Database
XfnQP_N= 1 # [EXTQP Xd] Interpolation neighbours
% XfnQP_E
0.000000 | 1.000000 | 1.000000 | # [EXTQP Xd] E parameters (c/v) eV|adim|adim
%
XfnQP_Z= ( 1.000000 , 0.000000 ) # [EXTQP Xd] Z factor (c/v)
XfnQP_Wv_E= 0.000000 eV # [EXTQP Xd] W Energy reference (valence)
% XfnQP_Wv
0.00 | 0.00 | 0.00 | # [EXTQP Xd] W parameters (valence) eV|adim|eV^-1
%
XfnQP_Wc_E= 0.000000 eV # [EXTQP Xd] W Energy reference (conduction)
% XfnQP_Wc
0.00 | 0.00 | 0.00 | # [EXTQP Xd] W parameters (conduction) eV|adim|eV^-1
%
% Qdirection
0.00 | 0.00 | 0.00 | # [Xd] Transferred momentum direction (iku)
%
QShiftOrder= 1 # [Xd] Pick-up the (QShiftOrder)th q+G vector

Dear Sener,

Please let me ask to post your question in the right subforum. The present topic has nothing to do with the Yambo postprocessing Ypp.
An ordered forum is more useful for everybody.

Coming to your question: the calculation is in linear response so the magnitude of the electric field here is irrelevant, and the variable you are mentioning is needed to identify the direction of the electric field when considering the q-->0 limit.
Most probably you can still calculate the enhancement but you need to check that when dealing with linear response.
Best,
Daniele

I am going to post this under technical issues topic is that okay or should i post this under another topic?

sener

Dear Sener,
I would post it under "Running Yambo", either in Linear Response or in Other issues.

Best,

Daniele