Error while performing a real time calculation for hBN

[Bramhachari Khamari]

Dear developer,
I would like to reproduce the result of Linear response in real time for hBN. I followed the following step (as given in Lumen tutorials) to get the result,

step1: pw.x
step2: p2y
step3: yambo_rt (set up run for real time)
step4: ypp_rt -y (To reduce the symmetry), then I run ypp_rt, thereby the folder Fixsymm is created
step5: yambo_rt is executed inside the Fixsymm.
step6: yambo_nl -u to calculate linear response in real time. this run produces a input file as follows,

nloptics # [R NL] Non-linear optics
% NLBands
3 | 6 | # [NL] Bands
%
NLverbosity= "low" # [NL] Verbosity level (low | high)
NLtime=-1.000000 fs # [NL] Simulation Time
NLCorrelation= "IPA" # [NL] Correlation ("IPA/HARTREE/TDDFT/LRC/LRW/JGM/SEX")
NLLrcAlpha= 0.000000 # [NL] Long Range Correction
% NLEnRange
0.200000 | 8.000000 | eV # [NL] Energy range
%
NLEnSteps= 80 # [NL] Energy steps
NLDamping= 0.200000 eV # [NL] Damping
NLGvecs= 6021 RL # [NL] Number of G vectors in NL dynamics for Hartree/TDDFT
% ExtF_Dir
1.000000 | 0.000000 | 0.000000 | # [NL ExtF] Versor
%

When I run the calculation with the command yambo_nl,
I got the error message,

ERROR] STOP signal received while in :[03.01] Initialization
[ERROR] Non-linear optics works only in double precision, configure with --enable-dp flag
application called MPI_Abort(MPI_COMM_WORLD, 1) - process 0.

I have installed yambo 4.4.0. Could you tell me the steps to be followed for rela time calculation.

[claudio]

Dear Bramhachari Khamari

this problem is easy to solve.
Normally Yambo is compiled in single precision, but non-linear response requires double precision to work.
In order to compile yambo in double precision
go in the yambo folder, do

make distclean

reconfigure yambo and add the flag --enable-dp to the configure

./configure --enable-dp

recompile all executables.
And now you can run the non-linear optics simulations

best
Claudio

[Bramhachari Khamari]

Dear Sir,
Thank you for the reply.

Regards,
Bramha