## reciprocal lattice and k-lattice mismatch

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neha_kapila
Newbie
Posts: 10
Joined: Thu Feb 18, 2021 3:08 pm

### reciprocal lattice and k-lattice mismatch

hello,
I am trying to relax Mos2-ZnO hetero structure but got error'
VERY BAD NEWS! internal error in subroutine IBZKPT:
Reciprocal lattice and k-lattice belong to different class of lattices. Often results are still useful... 96
Please someone tell me how to solve it.
I have tried kmesh1010x1,12x12x1 and also 20x20x1 as i want to study two dimensional structure.
I am new to vasp please forgive my mistakes
SYSTEM = MoS2_ZnO
ISTART = 0
#ISPIN = 1
ICHARG = 2
ISMEAR = -5 ! Tetrahedron
ENCUT = 550
PREC = Normal
IBRION = 2
ISIF = 2
NSW = 300
NELMIN = 6
EDIFF = 0.00001
EDIFFG = -0.01
LCHARG = .TRUE.
#LREAL = Auto
IVDW = 1

K-POINTS_HEXAGONAL CELL
0
Monkhorst-Pack
21 21 1
0 0 0

MoS2_ZnO
1.0
3.2003099918 0.0000000000 0.0000000000
-1.5981826900 2.7734376691 0.0000000000
0.0000000000 0.0000000000 20.0000000000
Mo S Zn O
1 2 1 1
Cartesian
1.580990023 0.911285052 8.927399516
-0.038334903 1.822572913 7.675499916
-0.038334903 1.822572913 10.179300308
1.449333659 0.825272396 4.487999976
1.129196947 2.391221981 4.395800233

alex
Hero Member
Posts: 516
Joined: Tue Nov 16, 2004 2:21 pm
Location: Germany

### Re: reciprocal lattice and k-lattice mismatch

Hi,

try the gamma-centred mesh, e.g.

K-POINTS_HEXAGONAL CELL
0
Gamma
21 21 1
0 0 0

neha_kapila
Newbie
Posts: 10
Joined: Thu Feb 18, 2021 3:08 pm

### Reciprocal lattice and k lattice mismatch in heterostructure,vaspkit error message

kindly check my inputs for MOs2_ZnO heterostructure. The structure is relaxed and scf is done with GGA_PBE but I am getting the following error while running for DOS
VERY BAD NEWS! internal error in subroutine IBZKPT:
Reciprocal lattice and k-lattice belong to different class of lattices. Often results are still useful... 96
SYSTEM = MoS2_ZnO
ISTART = 0
ISPIN = 1
ICHARG = 11
ISMEAR = -5 !
ENCUT = 500
PREC = Accurate
#SYMPREC = 0.0000001
IBRION = -1
#ISIF = 2
NSW = 0
EDIFF = 0.00001
EDIFFG = -0.01
LCHARG = .TRUE.
IVDW = 1
LORBIT = 11
NEDOS = 2000
EMAX = 10
EMIN = -10
#GGA+U
LDAU = .TRUE.
LDAUTYPE = 2
LDAUL = -1 -1 2 1
LDAUU = 0 0 10.9 8.4
LDAUJ = 0 0 0 0
LDAUPRINT = 2
LMAXMIX = 4
LASPH = .TRUE.

K-POINTS_HEXAGONAL CELL
0
Gamma
24 24 1
0. 0. 0.

MoS2_ZnO
1.000
3.1603099918000002 0.0000000000000000 0.0000000000000000
-1.5821826900000000 2.7634376691000000 0.0000000000000000
0.0000000000000000 0.0000000000000000 20.0000000000000000
Mo S Zn O
1 2 1 1
Cartesian
1.4499074360098474 0.8204209585494312 11.4557014106349691 Mo1
-0.1306564522771366 1.7443135769948761 9.8941809272645127 S1
-0.1307417832789958 1.7444931994609048 13.0204999726209589 S2
1.4480464160661553 0.8144298783693860 6.9994904552128414 Zn1
1.4462952064801122 2.6492676416254053 6.9795000273790411 O1
even if i am trying to generate k path using vaspkit its giving me the following error
See An Example in vaspkit/examples/seek_kpath/graphene_2D.
More details are given in arXiv:1806.04285 (2018) and refs.
This feature is still experimental & check PRIMCELL.vasp file.
+---------------------------------------------------------------+
-->> (01) Reading Structural Parameters from POSCAR File...
forrtl: severe (174): SIGSEGV, segmentation fault occurred
Image PC Routine Line Source
vaspkit 00000000007D6753 Unknown Unknown Unknown
vaspkit 000000000070A382 get_transformed_c 1 transformedcell.F90
vaspkit 000000000070C0EA standardize_2d_ce 28 standardize2d.F90
vaspkit 00000000006EBA20 get_2d_kpath_ 19 kpath2d.F90
vaspkit 000000000064183F get_kpaths_ 26 getkpath.F90
vaspkit 0000000000656E31 MAIN__ 20 main.F90
vaspkit 0000000000408062 Unknown Unknown Unknown
libc-2.31.so 00007FF75C16B0B3 __libc_start_main Unknown Unknown
vaspkit 0000000000407F69 Unknown Unknown Unknown

neha_kapila
Newbie
Posts: 10
Joined: Thu Feb 18, 2021 3:08 pm

### Re: reciprocal lattice and k-lattice mismatch

thank you so much Alex
I tried that but its not working,however if I change the lattice constant then it works but then the Band-structure is different.

martin.schlipf
Global Moderator
Posts: 164
Joined: Fri Nov 08, 2019 7:18 am

### Re: reciprocal lattice and k-lattice mismatch

Please note that the VASPKIT software is neither developed nor supported by us. You need to contact the developers of that software for more information.
neha_kapila wrote:
Sun Jun 13, 2021 8:44 am
I tried that but its not working,however if I change the lattice constant then it works but then the Band-structure is different.
Could you expand a bit on this, what is not working and what other error do you get if you change the lattice constant?