Yambo Community Forum

Hello,
I try to calculate the dielectric function of iron pnictides. These are metalls so I have to give the Drude-parameters in the input file.
My input file looks like this:

# __ __ ________ ___ __ __ _______ ______
# /_/\/_/\ /_______/\ /__//_//_/\ /_______/\ /_____/\
# \ \ \ \ \\::: _ \ \\::\| \| \ \\::: _ \ \\:::_ \ \
# \:\_\ \ \\::(_) \ \\:. \ \\::(_) \/_\:\ \ \ \
# \::::_\/ \:: __ \ \\:.\-/\ \ \\:: _ \ \\:\ \ \ \
# \::\ \ \:.\ \ \ \\. \ \ \ \\::(_) \ \\:\_\ \ \
# \__\/ \__\/\__\/ \__\/ \__\/ \_______\/ \_____\/
#
# GPL Version 3.4.1 Revision 3187
# http://www.yambo-code.org
#
optics # [R OPT] Optics
chi # [R CHI] Dyson equation for Chi.
Chimod= "IP" # [X] IP/Hartree/ALDA/LRC/BSfxc
% QpntsRXd
1 | 1 | # [Xd] Transferred momenta
%
% BndsRnXd
10 | 45 | # [Xd] Polarization function bands
%
% EnRngeXd
0.00000 | 10.00000 | eV # [Xd] Energy range
%
% DmRngeXd
0.10000 | 0.10000 | eV # [Xd] Damping range
%
ETStpsXd= 100 # [Xd] Total Energy steps
% LongDrXd
1.000000 | 0.000000 | 0.000000 | # [Xd] [cc] Electric Field
%
%DrudeWXd
0.578000 | 0.006820 | eV # [Xd] Drude plasmon
%

Starting the calculation I receive the warning:
<08s> [WARNING]Metallic system

My output file for epsilon looks like this:
#
# ** ** ** **** **** ****** *******
# //** ** **** /**/** **/** /*////** **/////**
# //**** **//** /**//** ** /** /* /** ** //**
# //** ** //** /** //*** /** /****** /** /**
# /** **********/** //* /** /*//// **/** /**
# /** /**//////**/** / /** /* /**//** **
# /** /** /**/** /** /******* //*******
# // // // // // /////// ///////
#
# GPL Version 3.4.1 Revision 3187
# http://www.yambo-code.org
#
# Absorption @ Q(1) [q->0 direction] : 1.0000000 0.0000000 0.0000000
#
#
# - Energies are Perdew, Burke & Ernzerhof(X)+Perdew, Burke & Ernzerhof(C)
# - Wavefunctions are Perdew, Burke & Ernzerhof(X)+Perdew, Burke & Ernzerhof(C)
#
# - The Green`s function is causal -
# - Using Shifted Grids -
# - [r,Vnl] *is* included -
#
# E/ev[1] eps /Im[2] eps /Re[3]
#
0.0000 -.54389E-7 78.078
0.101010 21.181532 54.240448
0.202020 15.026344 47.033325
0.303030 16.675797 47.116310
0.404040 20.504234 44.761200
...
...
...
9.7979794 2.2414825 -2.3654292
9.8989897 2.2402058 -2.2296402
10.000000 2.269330 -2.167766
#
# YAMBO@QuanQal2 x 001 CPUs * 05/26/2015 10:54 [start]
# 05/26/2015 22:38 [end]
#
# Cpu Timing [Min/Max/Average]: 11h-33m-19s/11h-33m-19s/11h-33m-19s
#
# .-Input file : yambo.in
# | optics # [R OPT] Optics
# | chi # [R CHI] Dyson equation for Chi.
# | BoseTemp= 0.02585 eV # Bosonic Temperature
# | FFTGvecs= 11471 RL # [FFT] Plane-waves
# | Chimod= "IP" # [X] IP/Hartree/ALDA/LRC/BSfxc
# | % QpntsRXd
# | 1 | 1 | # [Xd] Transferred momenta
# | %
# | % BndsRnXd
# | 10 | 45 | # [Xd] Polarization function bands
# | %
# | GrFnTpXd= "c" # [Xd] Green`s function t/c/r/a
# | % EnRngeXd
# | 0.00000 | 10.00000 | eV # [Xd] Energy range
# | %
# | % DmRngeXd
# | 0.10000 | 0.10000 | eV # [Xd] Damping range
# | %
# | ETStpsXd= 100 # [Xd] Total Energy steps
# | % LongDrXd
# | 0.1000E-4 | 0.000 | 0.000 | # [Xd] [cc] Electric Field
# | %


In the output file no Drude plasmon is mentioned. Is it not involved in the calculation?
Have I made a mistake in the input-file?
Also strange is the fact that LongDRXd in the output file is not the parameter I chose in the input. Is this just to lower the strength of the electric field?

Thanks and regards

Stephan

Dear Stephan,

is it the Drude variable reported at the end of the report file? If it is not recognized Yambo should warn you in the report that the system is metallic and you are *not* using the Drude model for the iterband transistion.
An\bout LongDRXd, it is the q direction of the field. In input you give the directions, next when calculating the spectrum limit q-->0 has to be done, so a small value of q in that directions is considered, and this small value of q is reported in the output/report.

If the Drude variable is effectively not read, please post here the input/report files and we will investigate.

Best,
Daniele

Dear Daniele,

thank you for your quick reply. In the report file I found, that the Drude variable is definitely not read.
In the attachment you find the input-file. Do I make any mistakes in the syntax of the input file?
The report files are too huge to upload. I post the most important lines of the r_optics_chi-file here:


** ** ** **** **** ****** *******
//** ** **** /**/** **/** /*////** **/////**
//**** **//** /**//** ** /** /* /** ** //**
//** ** //** /** //*** /** /****** /** /**
/** **********/** //* /** /*//// **/** /**
/** /**//////**/** / /** /* /**//** **
/** /** /**/** /** /******* //*******
// // // // // /////// ///////

GPL Version 3.4.1 Revision 3187
http://www.yambo-code.org

YAMBO@QuanQal2 x 001 CPUs * 05/26/2015 10:54

[01] Files & I/O Directories
============================

CORE databases in .
Additional I/O in .
Communications in .
Input file is yambo.in
Report file is ./r_optics_chi_06

[RD./SAVE//s.db1]-------------------------------------------
Bands : 50
K-points : 12195
G-vectors [RL space]: 66095
Components [wavefunctions]: 8298
Symmetries [spatial]: 2
Spinor components : 1
Spin polarizations : 1
Temperature [ev]: 0.02585
Electrons : 44.00000
WF G-vectors : 11470
Max atoms/species : 2
No. of atom species : 3
Magnetic symmetries : no
- S/N 008598 --------------------------- v.03.04.01 r.3187 -

[02] CORE Variables Setup
=========================


[02.01] Unit cells
==================

Unit cell is Unknown

... containing 1Ba2Fe2As atoms

... with scaling factors [a.u.]: 12.23154 5.30503 12.23154

Direct Lattice(DL) unit cell [iru / cc(a.u.)]
A1 = 0.430596 0.000000 1.000000 5.266856 0.000000 12.23154
A2 = 0.430596 1.000000 0.000000 5.266856 5.305028 0.000000
A3 = 0.000000 1.000000 1.000000 0.000000 5.305028 12.23154

DL volume [au]: 683.5182

Reciprocal Lattice(RL) unit cell [iku / cc]
B1 = 1.161180 -0.500000 0.500000 0.596484 -0.592192 0.256844
B1 = 1.161180 0.500000 -0.500000 0.596484 0.592192 -0.256844
B1 =-1.161180 0.500000 0.500000 -0.596484 0.592192 0.256844


[02.02] Symmetries
==================

DL (S)ymmetries [cc]
[S1] 1.000000 0.000000 0.000000 0.000000 1.000000 0.000000 0.000000 0.000000 1.000000
[S2]-1.000000 0.000000 0.000000 0.000000 -1.000000 0.000000 0.000000 0.000000 -1.000000

[SYMs] K-space Time-reversal not included
[SYMs] Spatial inversion 2 is a symmetry
[SYMs] Group table built correctly

[02.03] RL shells
=================

Shells, format: [S#] G_RL(mHa)

[S8707]:66095(0.1600E+6) [S8706]:66087(0.1599E+6) [S8705]:66079(0.1599E+6) [S8704]:66071(0.1599E+6)
[S8703]:66063(0.1599E+6) [S8702]:66055(0.1599E+6) [S8701]:66051(0.1599E+6) [S8700]:66043(0.1599E+6)
[S8699]:66035(0.1599E+6) [S8698]:66027(0.1599E+6) [S8697]:66019(0.1599E+6) [S8696]:66011(0.1598E+6)
[S8695]:66003(0.1598E+6) [S8694]:65995(0.1598E+6) [S8693]:65987(0.1598E+6) [S8692]:65979(0.1598E+6)
[S8691]:65971(0.1598E+6) [S8690]:65963(0.1598E+6) [S8689]:65955(0.1598E+6) [S8688]:65951(0.1597E+6)
[S8687]:65943(0.1597E+6) [S8686]:65935(0.1597E+6) [S8685]:65927(0.1597E+6) [S8684]:65919(0.1597E+6)
[S8683]:65911(0.1597E+6) [S8682]:65903(0.1597E+6) [S8681]:65895(0.1597E+6) [S8680]:65887(0.1597E+6)
...
[S12]:47( 1229.) [S11]:43( 1187.) [S10]:41( 1178.) [S9]:33( 843.5228)
[S8]:29( 833.3193) [S7]:25( 711.5853) [S6]:23( 701.3818) [S5]:21( 650.1009)
[S4]:13( 527.7495) [S3]:11( 386.2261) [S2]:3( 131.9374) [S1]:1( 0.000000)

[02.04] K-grid lattice
======================

Compatible Grid is 3D
B1 [rlu]= -0.06667 0.00000 -0.06667
B2 =0.8941E-7 0.9313E-7 -.6667E-1
B3 =-.4843E-7 -.6667E-1 -.5215E-7
Grid dimensions : 15 15 15
K lattice UC volume [au]:0.1075E-3

[02.05] Energies [ev] & Occupations
===================================

Fermi Level [ev]: 8.717769
Electronic Temp. [ev K]: 0.2585E-1 300.0
Bosonic Temp. [ev K]: 0.2585E-1 300.0
El. density [cm-3]: 0.434E+24
States summary : Full Metallic Empty
0001-0019 0020-0024 0025-0050

[WARNING]Metallic system
N of el / N of met el: 44.00000 6.00424
Average metallic occ.: 1.200849
X BZ K-points : 24389

Energy unit is electronVolt [eV]
...
...
...

CpuTiming [Min/Max/Average]: 09s/09s/09s

[03] Transferred momenta grid
=============================

[RD./SAVE//db.kindx]----------------------------------------
Polarization last K : 12195
QP states : 1 12195
X grid is uniform :no
BS scattering :yes
- S/N 008598 --------------------------- v.03.04.01 r.3187 -

IBZ Q-points : 1
BZ Q-points : 1

Q [00001] : 0.00 0.00 0.00 (iku) * weight 1.000000

Q [00001] : 0.00 0.00 0.00 (cc ) * weight 1.000000

[04] Optics
===========

[WF loader] Normalization (few states) min/max :0.3096E-10 1.000


[WARNING] [x,Vnl] slows the Dipoles computation. To neglect it rename the ns.kb_pp file
[WR./SAVE//db.dipoles]--------------------------------------
Brillouin Zone Q/K grids (IBZ/BZ): 1 1 12195 24389
RL vectors (WF): 11471
Electronic Temperature [K]: 300.00000
Bosonic Temperature [K]: 300.00000
X band range : 10 45
X e/h energy range [ev]:-1.0000000 -1.0000000
Metallic bands : 24
Filled bands : 19
RL vectors in the sum : 11471
[r,Vnl] included :yes
Transitions ordered :yes
Using shifted grids :no
Field momentum norm :0.10000E-4
Wavefunctions :Perdew, Burke & Ernzerhof(X)+Perdew, Burke & Ernzerhof(C)
- S/N 008598 --------------------------- v.03.04.01 r.3187 -

[WARNING] The system is a metal but Drude term not included.
[X-CG] R(p) Tot o/o(of R) : 122801 8018067 100

CpuTiming [Min/Max/Average]: 11h-33m-09s/11h-33m-09s/11h-33m-09s

[05] Game Over & Game summary
=============================

YAMBO@QuanQal2 x 001 CPUs * 05/26/2015 10:54 [start]
05/26/2015 22:38 [end]

Cpu Timing [Min/Max/Average]: 11h-33m-19s/11h-33m-19s/11h-33m-19s

.-ACKNOWLEDGMENT
|
| The users of YAMBO have little formal obligations with respect to
| the YAMBO group (those specified in the GNU General Public
| License, http://www.gnu.org/copyleft/gpl.txt). However, it is
| common practice in the scientific literature, to acknowledge the
| efforts of people that have made the research possible. In this
| spirit, please find below the reference we kindly ask you to use
| in order to acknowledge YAMBO:
|
| Yambo: An ab initio tool for excited state calculations
| A. Marini, C. Hogan, M. Gr\"uning, D. Varsano
| Computer Physics Communications 180, 1392 (2009).
|

.-Input file : yambo.in
| optics # [R OPT] Optics
| chi # [R CHI] Dyson equation for Chi.
| BoseTemp= 0.02585 eV # Bosonic Temperature
| FFTGvecs= 11471 RL # [FFT] Plane-waves
| Chimod= "IP" # [X] IP/Hartree/ALDA/LRC/BSfxc
| % QpntsRXd
| 1 | 1 | # [Xd] Transferred momenta
| %
| % BndsRnXd
| 10 | 45 | # [Xd] Polarization function bands
| %
| GrFnTpXd= "c" # [Xd] Green`s function t/c/r/a
| % EnRngeXd
| 0.00000 | 10.00000 | eV # [Xd] Energy range
| %
| % DmRngeXd
| 0.10000 | 0.10000 | eV # [Xd] Damping range
| %
| ETStpsXd= 100 # [Xd] Total Energy steps
| % LongDrXd
| 0.1000E-4 | 0.000 | 0.000 | # [Xd] [cc] Electric Field
| %


I hope this is enough to find my mistake. Otherwise I would need another possibility to send you the file.


For LongDRXd I found the following description on the web-page:
"Long description
This vector defines the Electric field vector direction used when performing the q->0 limit in the evaluation of the dielectric function. "

Since it is said this vector describes the electric field vector I suggested the polarization of the light is ment.
Is there any other possibility to define a certain polarization?

Thanks and regards,
Stephan

Dear Stephan,
I will have a look to the problem of the Drude variable.

About LongDRXd

Since it is said this vector describes the electric field vector I suggested the polarization of the light is ment.
Is there any other possibility to define a certain polarization?

Indeed, it is the light polarization direction.

Daniele

Dear Stephan,
I had a look to your input. Unfortunately I could not check exactly in the version you are using as I have the server down, anyway it looks to me that
the Drude term is not recognized as the syntax in your input file is wrong:

The correct syntax is e.g:
while you are using:
Did you activate the variable using the verbosity -V resp, or you added the variable by hand in the input? As I also noticed that in the online input manual there is some confusion with this variable.
Best,
Daniele