exercise/06 diamond

Carbon in A4 structure.

2 Fcc lattice shift along the diagonal from (0,0,0) to (1/4,1/4,1/4)

 1KSTR      HP......=N                               22 Jan 08
 2JOBNAM...=A4         MSGL.=  1 MODE...=B STORE..=Y HIGH...=Y
 3DIR001=smx/
 4DIR006=./
 5Slope matrices, l21 (spdf), (kappa*w)^2= 0.0
 6NL.....= 3 NLH...=11 NLW...= 9 NDER..= 6 ITRANS= 3 NPRN..= 0
 7(K*W)^2..=  0.000000 DMAX....=    1.0980 RWATS...=      0.10
 8NQ3...=  2 LAT...= 2 IPRIM.= 0 NGHBP.=13 NQR2..= 0
 9A........= 1.0000000 B.......= 1.0000000 C.......= 1.0000000
10BSX......= 0.5000000 BSY.....= 0.5000000 BSZ.....= 0.0000000
11BSX......= 0.0000000 BSY.....= 0.5000000 BSZ.....= 0.5000000
12BSX......= 0.5000000 BSY.....= 0.0000000 BSZ.....= 0.5000000
13QX(IQ)...= 0.0000000 QY......= 0.0000000 QZ......= 0.0000000
14QX(IQ)...= 0.2500000 QY......= 0.2500000 QZ......= 0.2500000
15a/w(IQ)..= 0.70 0.70 0.70 0.70
16a/w(IQ)..= 0.70 0.70 0.70 0.70
17LAMDA....=    2.5000 AMAX....=    4.5000 BMAX....=    4.5000

Run kstr for this A4 structure, check the output file if there are some warnings. Will be problem ?

How about we also fill up the (1/2,1/2,1/2) and (3/4,3/4,3/4), what lattice it should be?

 1KSTR      HP......=N                               22 Jan 08
 2JOBNAM...=L21        MSGL.=  1 MODE...=B STORE..=Y HIGH...=Y
 3DIR001=smx/
 4DIR006=./
 5Slope matrices, l21 (spdf), (kappa*w)^2= 0.0
 6NL.....= 3 NLH...=11 NLW...= 9 NDER..= 6 ITRANS= 3 NPRN..= 0
 7(K*W)^2..=  0.000000 DMAX....=    1.0980 RWATS...=      0.10
 8NQ3...=  4 LAT...= 2 IPRIM.= 0 NGHBP.=13 NQR2..= 0
 9A........= 1.0000000 B.......= 1.0000000 C.......= 1.0000000
10BSX......= 0.5000000 BSY.....= 0.5000000 BSZ.....= 0.0000000
11BSX......= 0.0000000 BSY.....= 0.5000000 BSZ.....= 0.5000000
12BSX......= 0.5000000 BSY.....= 0.0000000 BSZ.....= 0.5000000
13QX(IQ)...= 0.0000000 QY......= 0.0000000 QZ......= 0.0000000
14QX(IQ)...= 0.2500000 QY......= 0.2500000 QZ......= 0.2500000
15QX(IQ)...= 0.5000000 QY......= 0.5000000 QZ......= 0.5000000
16QX(IQ)...= 0.7500000 QY......= 0.7500000 QZ......= 0.7500000
17a/w(IQ)..= 0.70 0.70 0.70 0.70
18a/w(IQ)..= 0.70 0.70 0.70 0.70
19a/w(IQ)..= 0.70 0.70 0.70 0.70
20a/w(IQ)..= 0.70 0.70 0.70 0.70
21LAMDA....=    2.5000 AMAX....=    4.5000 BMAX....=    4.5000

Check the CMDL value from its output, and compare with bcc (exercise/04/kstr/bcc.prn)

grep CMDL L21.prn
grep ../04/kstr/bcc.prn

Let’s use this more “close packed” structure for diamond

 1KGRN                                               13 Oct 12
 2JOBNAM=c
 3STRT..=  A MSGL.=  0 EXPAN.= M FCD..=  Y FUNC..= SCA
 4FOR001=../kstr/smx/L21.tfh
 5FOR001=../kstr/smx/L21p.tfh
 6DIR002=pot/
 7DIR003=pot/
 8FOR004=../bmdl/mdl/L21.mdl
 9DIR006=
10DIR009=pot/
11DIR010=chd/
12DIR011=/tmp/
13Self-consistent KKR calculation for A4 C
14Band: 10 lines
15NITER.= 50 NLIN.= 31 NPRN.=  0 NCPA.=  7 NT...=  4 MNTA.=  1
16MODE..= 3D FRC..=  N DOS..=  N OPS..=  N AFM..=  P CRT..=  I
17Lmaxh.=  8 Lmaxt=  3 NFI..= 31 FIXG.=  2 SHF..=  0 SOFC.=  Y
18KMSH...= G IBZ..=  2 NKX..=  0 NKY..= 13 NKZ..=  0 FBZ..=  N
19KMSH2..= G IBZ2.=  1 NKX2.=  4 NKY2.=  0 NKZ2.= 51
20ZMSH...= C NZ1..= 32 NZ2..=  8 NZ3..=  8 NRES.=  4 NZD.= 800
21DEPTH..=  2.000 IMAGZ.=  0.020 EPS...=  0.200 ELIM..= -1.000
22AMIX...=  0.050 EFMIX.=  1.000 VMTZ..=  0.000 MMOM..=  0.000
23TOLE...= 1.d-07 TOLEF.= 1.d-07 TOLCPA= 1.d-06 TFERMI=  500.0 (K)
24SWS......=1.650000   NSWS.=  1 DSWS..=   0.05 ALPCPA= 0.6020
25Setup: 2 + NQ*NS lines
26EFGS...=  0.000 HX....=  0.200 NX...=  5 NZ0..= 16 STMP..= A
27Symb   IQ IT ITA NZ  CONC   Sm(s)  S(ws) WS(wst) QTR SPLT Fix
28C       1  1  1   6  1.000  1.000  1.000  1.000  0.0  0.0  N
29C       2  2  1   6  1.000  1.000  1.000  1.000  0.0  0.0  N
30Em      3  3  1   0  1.000  1.000  1.000  1.000  0.0  0.0  N
31Em      4  4  1   0  1.000  1.000  1.000  1.000  0.0  0.0  N
32Atom:  4 lines + NT*NTA*6 lines
33IEX...=  4 NP..= 251 NES..= 15 NITER=100 IWAT.=  0 NPRNA=  0
34VMIX.....=  0.300000 RWAT....=  3.500000 RMAX....= 20.000000
35DX.......=  0.030000 DR1.....=  0.002000 TEST....=  1.00E-12
36TESTE....=  1.00E-12 TESTY...=  1.00E-12 TESTV...=  1.00E-12
37C
38Iz=   6 Norb=  3 Ion=  0 Config= 2s2 2p2
39n      1  2  2
40Kappa -1 -1  1
41Occup  2  2  2
42Valen  0  1  1
43C
44Iz=   6 Norb=  3 Ion=  0 Config= 2s2 2p2
45n      1  2  2
46Kappa -1 -1  1
47Occup  2  2  2
48Valen  0  1  1
49Em
50Iz=   0 Norb=  0 Ion=  0 Config= 1s0
51n      1
52Kappa -1
53Occup  0
54Valen  1
55Em
56Iz=   0 Norb=  0 Ion=  0 Config= 1s0
57n      1
58Kappa -1
59Occup  0
60Valen  1

  • Em: empty sites

  • CRT..=  I

  • kstr: NL.....= 3

Lattice constants for diamond ?

Convert to SWS ?

Hint

diamond structure in cubic conventional cells contains 8 atoms, we add extra 8 emtpy sites:

\[16\times \frac{4\pi}{3} \omega^3 = a^3\]

Eqation of state for diamond

 1#! /bin/bash
 2
 3mkdir -vp diamond/kgrn/{chd,pot}
 4mkdir -vp diamond/kfcd/
 5
 6cd diamond
 7ln -s ../kstr
 8ln -s ../shape
 9ln -s ../bmdl
10cd -
11
12for sws in `seq 1.60 0.02 1.70`
13do
14  sed -e "s/JOBNAM=.*/JOBNAM=c_${sws}/" \
15      -e "s/SWS......=......../SWS......=${sws}0000/" \
16      kgrn/c.dat > diamond/kgrn/c_${sws}.dat
17
18  sed -e "s/JOBNAM...=.*/JOBNAM...=c_${sws}/" \
19      kfcd/c.dat > diamond/kfcd/c_${sws}.dat
20done

Maybe Heusler Alloy ?