I am doing a gw calculation on a 0D system containing 40 atoms using yambo 4.3.2 and "yambo -g n -p p -V par -r" to generate input file as

The input file as"

gw0 # [R GW] GoWo Quasiparticle energy levels

ppa # [R Xp] Plasmon Pole Approximation

rim_cut # [R RIM CUT] Coulomb potential

HF_and_locXC # [R XX] Hartree-Fock Self-energy and Vxc

em1d # [R Xd] Dynamical Inverse Dielectric Matrix

NLogCPUs=8 # [PARALLEL] Live-timing CPU`s (0 for all)

PAR_def_mode= "workload" # [PARALLEL] Default distribution mode ("balanced"/"memory"/"workload")

X_all_q_CPU= "1 1 9 8" # [PARALLEL] CPUs for each role

X_all_q_ROLEs= "q k c v" # [PARALLEL] CPUs roles (q,k,c,v)

X_all_q_nCPU_LinAlg_INV= 4 # [PARALLEL] CPUs for Linear Algebra

X_Threads=8 # [OPENMP/X] Number of threads for response functions

DIP_Threads=8 # [OPENMP/X] Number of threads for dipoles

SE_Threads=8 # [OPENMP/GW] Number of threads for self-energy

SE_CPU= "1 1 72" # [PARALLEL] CPUs for each role

SE_ROLEs= "q qp b" # [PARALLEL] CPUs roles (q,qp,b)

RandQpts= 2000000 # [RIM] Number of random q-points in the BZ

RandGvec= 123 RL # [RIM] Coulomb interaction RS components

CUTGeo= "box XYZ" # [CUT] Coulomb Cutoff geometry: box/cylinder/sphere X/Y/Z/XY..

% CUTBox

45.50000 | 45.50000 | 45.50000 | # [CUT] [au] Box sides

%

CUTRadius= 0.000000 # [CUT] [au] Sphere/Cylinder radius

CUTCylLen= 0.000000 # [CUT] [au] Cylinder length

CUTwsGvec= 0.700000 # [CUT] WS cutoff: number of G to be modified

EXXRLvcs= 90737 RL # [XX] Exchange RL components

FFTGvecs= 90737

Chimod= "Hartree" # [X] IP/Hartree/ALDA/LRC/PF/BSfxc

% BndsRnXp

1 | 360 | # [Xp] Polarization function bands

%

NGsBlkXp= 4 Ry # RL # [Xp] Response block size

% LongDrXp

1.000000 | 0.000000 | 0.000000 | # [Xp] [cc] Electric Field

%

PPAPntXp= 27.21138 eV # [Xp] PPA imaginary energy

% GbndRnge

1 | 400 | # [GW] G[W] bands range

%

GDamping= 0.10000 eV # [GW] G[W] damping

dScStep= 0.10000 eV # [GW] Energy step to evaluate Z factors

DysSolver= "n" # [GW] Dyson Equation solver ("n","s","g")

%QPkrange # [GW] QP generalized Kpoint/Band indices

1| 1| 55|66|

%

""

The calculation finished normally, but I found the correction of qp gap is strange showing "NaN" in gw.qp file containg the GW correction.

#

# __ __ ________ ___ __ __ _______ ______

# /_/\/_/\ /_______/\ /__//_//_/\ /_______/\ /_____/\

# \ \ \ \ \\::: _ \ \\::\| \| \ \\::: _ \ \\:::_ \ \

# \:\_\ \ \\::(_) \ \\:. \ \\::(_) \/_\:\ \ \ \

# \::::_\/ \:: __ \ \\:.\-/\ \ \\:: _ \ \\:\ \ \ \

# \::\ \ \:.\ \ \ \\. \ \ \ \\::(_) \ \\:\_\ \ \

# \__\/ \__\/\__\/ \__\/ \__\/ \_______\/ \_____\/

#

#

# GPL Version 4.3.2 Revision 134. (Based on r.15658 h.afdb12

# MPI+OpenMP Build

# http://www.yambo-code.org

#

# GW [Newton Solver]

#

# PPA imaginary pt [ev]: 27.21138

# RIM G`s : 123

# RIM random pts : 2000000

# GW SC iterations :0

# dS/dw steps : 2

# dS/dw step [ev]: 0.10000

# X G`s [used]: 14363

# X G`s [disk]: 14363

# X bands : 1 360

# X poles [o/o]: 100.0000

# X e/h E range [ev]:-1.000000 -1.000000

# X xc-Kernel : none

# X BZ energy Double Grid: no

# X BZ Double Grid points:0

# Sc/G bands : 1 400

# Sc/G damping [ev]: 0.10000

# Sc bands terminator : no

# Sx RL components : 90879

# QP @ K 001 - 001 : b 055 - 066

#

# K-point Band Eo E-Eo Sc|Eo

#

1.00000 55.00000 -0.36408 NaN NaN

1.00000 56.00000 -0.20616 NaN NaN

1.00000 57.00000 -0.10570 NaN NaN

1.00000 58.00000 -0.09662 NaN NaN

1.00000 59.00000 -0.09638 NaN NaN

1.00000 60.00000 0.00000 NaN NaN

1.00000 61.00000 1.77565 NaN NaN

1.00000 62.00000 2.15941 NaN NaN

1.00000 63.00000 2.15947 NaN NaN

1.00000 64.00000 2.40576 NaN NaN

1.00000 65.00000 2.80214 NaN NaN

1.00000 66.00000 2.87236 NaN NaN

"

What 's the reason and how to fix it?? THanks a lot.

Best