ABCAP : beginners — qsub sh —August 23, 2020

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Band Structure Calculation

3.1

Ferromagnetic Fe

Prepare a directory for the calculation:
Purpose:----------------------------cd ~/abc
mkdir Fe
cd Fe../Setnew.sh-----------------------------(1) Study the symmetry of crystal (symmetry operations).
(2) Study the ferromagnetic state.
(3) Study the symmetry of wavefunction (irreducible
representations).

Enter a command, H, which shows a procedure of thecalculation.
The procedure consists of(4) Study the optical transition between valence andconduction bands (dipole allowed).

• Edit a file, ???.data.
• Execute a shell-script file, ???.sh.

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Environment variables[1] Edit the file, ab_prp.data by using the following
information:

Let’s use bash.
In order to set some environment variables, executethe following commands:>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
Fe
a=2.87A (229, Oh9, Im-3m)
body-centered (il=3) cubic latticegenerators
5 (0, 0, 0)
19 (0, 0, 0)
25 (0, 0, 0)
atomic position (0.0, 0.0, 0.0)
magnetic (jmag=2)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>---------------------------------------------cat /home/CMD/teac02/Bash_envs >> ~/.bash_profile
source ~/.bash_profile----------------------------------------------

The content of this Bash_envs file is######### Bash_envs ###########
export ABCAP=’/home/CMD/teac02/abcap1707’----------------------------(ab_prp.data)
ab_prp.qsub-----------------------------

export FC_TYPE=’gen’
export
FC=’ifort’
exportFO=export
MPIFC=’mpif90’
exportMPIFO=

Execute ab_prp.qsub: This is used for executing
ab_prp.sh.
It makes a file, ab_input.data, which is a real input file for the ABCAP calculation.

export PATH=.:$HOME/bin:$PATH
export HOSTNAME=‘hostname‘######### Bash_envs ###########

2

The file, ab_input.data, is made from the informations of ab_prp.data and atom.data. Theatom.data file is a data base for atoms from H toU.

Preparation[2] Calculate the initial charge density:

Make a directory, e.g., abc, for the ABCAP calculation.
Copy a shell-script file, Setnew.sh, as follows.

----------------------------(ab_input.data) ab_in.qsub---------------------------------------------------------cd ~mkdir abc
cp $ABCAP/samples/Setnew.sh abc/-----------------------------In ab_in.qsub, the following programs run.
• ab_in.exe checks the crystal structure, andmakes totally-symmetric basis functions.
• ab_inch.exe makes the initial charge density
as the superposition of atomic charge densities.

The shell-script file, Setnew.sh, is used on starting a
new calculation: Files needed for ABCAP calculation
are copied from the directory,$ABCAP/samples/LaMnO3c_f_6/.

• ab_kpgn.exe generates the k points used in
the calculation.
1• ab_size.exe estimates the size of calculation.

• plot.ps is obtained, which shows he k-spacepath in the e-k curve.

• ab_ospw.exe calculates the overlap integral
among the totally symmetric basis functions.

[7] Drawing of the density of states (DOS)• fl_dm00.exe sets the initial value of the local
density matrix. (diagonal elements are 1/2)

• Edit bn_pdos.data. Give the energy region
to be drawn.

[3] Iteration for the selfconsistent calculation. Edit

• Run bn_pdos.sh.

fl06.sh and set the number of iteration at the parameter, ITER_MAIN.

• Edit p2_dos.data. Select the total DOS, thes, p, d, and f partial DOS.
• Run p2_dos.sh----------------------------(ab_input.data) fl06.qsub-----------------------------•

In fl06.qsub, the following programs run:•fl_pot.exe makes the potential from thecharge densty.

3.2• fl_potuj.exe makes the +U potential fromthe local density matrix.

• fl_chg.exe determines the Fermi energy andcalculate the charge desity from the eigen functions.
• fl_dmmx.exe calculates the local density matrix.
• fl_pot.exe calculates the total energy.

In ’magnetic state’ section in the ab_prp.data file,the jmag0 parameter should be 0, namely,

fl_mx5.exe calculates the next input ofcharge density.

magnetic state-2----*----3----*----4----*0!jmag0 !noSO:(0(N),1(AF),2(M))----------------------------------------------

Here, fl_ptuj.exe works only with lda+u> 0.
A summary on each cycle of the iterative calculation is written in the file, iter.log. The summaryis shown on the display by the commnad,

3.3

Antiferromagnetic Cr>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>Cr andiferromagnetic (221, Oh1, Pm-3m)
a=2.88A (bcc)
simple (il=1) cubic lattice for AFM
generators
5 (0, 0, 0)
19 (0, 0, 0)
25 (0, 0, 0)
atomic positions (0.0, 0.0, 0.0)
(0.5, 0.5, 0.5)
antiferromagnetic (jmag=1)
operation 1 (1/2, 1/2, 1/2)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>----------------------------check.sh-----------------------------[4] Drawing of the crystal structure• Edit bn_atps.data. Give the region of drawing in the file.
• Run bn_atps.sh and p3_atps.sh.
• A postscript file, plot.ps, is obtained.

[5] Drawing of the band structure (e-k curve)

In ’magnetic state’ section in the ab_prp.data file,the jmag0 parameter should be 1, followed by the antiferromagnetic operation code, namely• Edit bnpl.data. Give paths in the k space tobe drawn.
• Run bnpl.sh.
•Nonmagnetic Si>>>>>>>>> ab_prp.data >>>>>>>>>>>
Si (227, Oh7, Fd-3m)
a=5.4296 A
face-centered (il=2) cubic latticegenerators
5 (0/1, 0/1, 0/1)
19 (1/4, 1/4, 1/4)
25 (1/4, 1/4, 1/4)
atomic position (0.0, 0.0, 0.0)
nonmagnetic (jmag=0)>>>>>>>>> ab_prp.data >>>>>>>>>>>• fl_bnd.exe calculates eigen functions
through a standard diagonalization.

•plot.ps is obtained for the nonmagnetic
case (jmag=0) or the antiferromagnetic case(jmag=1); plot1.ps and plot2.ps are obtained for the magnetic case (jmag=2).

magnetic state-2----*----3----*----4----*1!jmag0 !noSO:(0(N),1(AF),2(M))
1
1 2 1 2 1 2 !igen,jgen(2,3) for AF----------------------------------------------

plot.ps is obtained for the nonmagneticcase (jmag=0) or the antiferromagnetic case(jmag=1); plot1.ps and plot2.ps are obtained for the magnetic case (jmag=2).

Here, the antiferromagnetic operation means the symmetry operation which shows the relation between theup-spin state and the down-spin state.

[6] Drawing of the k-space path• Run brzone.sh.
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Symmorphic and Nonsymmorphic crystals

4.1

AlP>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
abcap-ab_compat.data2! the number of k points
0 0 0 1
! k point
1 0 0 8! k point>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>> ab_prp.data >>>>>>>>>>>AlP (216, Td2, F-43m) zinc blendea=5.45 A
face-centered (il=2) cubic latticegenerators
5 (0, 0, 0)
43 (0, 0, 0)
atomic positions(0.0, 0.0, 0.0 ) Al(0.25, 0.25, 0.25) P
nonmagnetic (jmag=0)>>>>>>>>> ab_prp.data >>>>>>>>>>>

4.2• Run ab_compat.sh.
• See ab_compat.log.

[3] Optical transition (dipole allowed)• Edit optsel.data: Give k points to be calculated.
>>>>>>>>>> optsel.data >>>>>>>>>>>>>
0! jpr (std output control)
0! idoub (0: noSOi or 1: SOi)
0 0 0 1 ! k-point
6! irrep. of vector (r or p)>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>

Si>>>>>>>>> ab_prp.data >>>>>>>>>>>
Si (227, Oh7, Fd-3m)
a=5.4296 A
face-centered (il=2) cubic latticegenerators
5 (0/1, 0/1, 0/1)
19 (1/4, 1/4, 1/4)
25 (1/4, 1/4, 1/4)
atomic position (0.0, 0.0, 0.0)
nonmagnetic (jmag=0)>>>>>>>>> ab_prp.data >>>>>>>>>>>

56• Run optsel.sh.
• See optsel.txt.

7

Crystal structures

NIMS database:
http://crystdb.nims.go.jp/crystdb/
search-materials

Space group information• Search ’nims’ and ’atomwork’ by using internet.

• generators:
File: generator.data• Click ”Enter AtomWork”• Wycoﬀ positions:File: wycoff.data• Input elements of the compound(example: Al P)
Click ”Search materials”.

• To make ab_prp.data,
there is a tool, ab_crystal.sh.

• Choose a structure.

• login.

• Choose a paper from the refernce list.
• See crystal structure (standardized).

The k group[1] Irreducible representations for the k group• Edit ab_irep.data: Give k points to be calculated.
>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>
abcap-ab_irep.data1! the number of k
0 0 0 1
! k point>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>>• Run ab_irep.sh.
• See ab_irep.log.

[2] Compatibility in k space•

Edit ab_compat.data: Give a series of kpoints for which you want to know the compatibility between the successive k points.
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