Line data Source code
1 : MODULE m_nmat21
2 : !------------------------------------------------------------
3 : !This subroutine calculates the density matrix n^{s}_{m,m'}
4 : !for a given atom 'n' and l-quantum number 'l'. The l's for
5 : !all atoms are stored in lda_u(), if lda_u()<0, no +U is used.
6 : !For details see Eq.(12) of Shick et al. PRB 60, 10765 (1999)
7 : !Part of the LDA+U package G.B., Oct. 2000
8 : !------------------------------------------------------------
9 :
10 : USE m_types
11 : USE m_constants
12 : USE m_symMMPmat
13 :
14 : IMPLICIT NONE
15 :
16 : CONTAINS
17 :
18 0 : SUBROUTINE n_mat21(atoms,sym,ne,we,denCoeffsOffdiag,eigVecCoeffs,n_mmp)
19 :
20 : TYPE(t_sym), INTENT(IN) :: sym
21 : TYPE(t_atoms), INTENT(IN) :: atoms
22 : TYPE(t_eigVecCoeffs), INTENT(IN) :: eigVecCoeffs
23 : TYPE(t_denCoeffsOffDiag), INTENT(IN) :: denCoeffsOffdiag
24 : INTEGER, INTENT(IN) :: ne
25 : REAL, INTENT(IN) :: we(:)!(input%neig)
26 : COMPLEX, INTENT(INOUT) :: n_mmp(-lmaxU_const:,-lmaxU_const:,:)
27 :
28 : INTEGER i,l,m,lp,mp,n,natom
29 : INTEGER ilo,ilop,ll1,lmp,lm,i_u
30 : COMPLEX c_0
31 :
32 : COMPLEX n_tmp(-lmaxU_const:lmaxU_const,-lmaxU_const:lmaxU_const)
33 :
34 : !
35 : ! calculate n_mat:
36 : !
37 0 : DO i_u = 1,atoms%n_u
38 0 : l = atoms%lda_u(i_u)%l
39 0 : n = atoms%lda_u(i_u)%atomType
40 0 : ll1 = (l+1)*l
41 0 : DO natom = atoms%firstAtom(n), atoms%firstAtom(n) + atoms%neq(n) - 1
42 0 : n_tmp = cmplx_0
43 : !
44 : ! prepare n_mat in local frame (in noco-calculations this depends
45 : ! also on alpha(n) and beta(n) )
46 : !
47 0 : DO m = -l,l
48 0 : lm = ll1+m
49 0 : DO mp = -l,l
50 0 : lmp = ll1+mp
51 0 : c_0 = cmplx_0
52 0 : DO i = 1,ne
53 : c_0 = c_0 + we(i) * ( &
54 : conjg(eigVecCoeffs%abcof(i,lmp,0,natom,2))*eigVecCoeffs%abcof(i,lm,0,natom,1) * denCoeffsOffdiag%uu21n(l,n) &
55 : + conjg(eigVecCoeffs%abcof(i,lmp,0,natom,2))*eigVecCoeffs%abcof(i,lm,1,natom,1) * denCoeffsOffdiag%ud21n(l,n) &
56 : + conjg(eigVecCoeffs%abcof(i,lmp,1,natom,2))*eigVecCoeffs%abcof(i,lm,0,natom,1) * denCoeffsOffdiag%du21n(l,n) &
57 0 : + conjg(eigVecCoeffs%abcof(i,lmp,1,natom,2))*eigVecCoeffs%abcof(i,lm,1,natom,1) * denCoeffsOffdiag%dd21n(l,n))
58 : ENDDO
59 0 : n_tmp(m,mp) = c_0
60 : ENDDO
61 : ENDDO
62 : !
63 : ! add local orbital contribution (if there is one) (untested so far)
64 : !
65 0 : DO ilo = 1, atoms%nlo(n)
66 0 : IF (atoms%llo(ilo,n).EQ.l) THEN
67 0 : DO m = -l,l
68 0 : lm = ll1+m
69 0 : DO mp = -l,l
70 0 : lmp = ll1+mp
71 0 : c_0 = cmplx_0
72 0 : DO i = 1,ne
73 : c_0 = c_0 + we(i) * ( &
74 : conjg(eigVecCoeffs%abcof(i,lmp,0,natom,2))*eigVecCoeffs%ccof(m,i,ilo,natom,1) * denCoeffsOffdiag%uulo21n(l,n) &
75 : + conjg(eigVecCoeffs%ccof(mp,i,ilo,natom,2))*eigVecCoeffs%abcof(i,lm,0,natom,1) * denCoeffsOffdiag%ulou21n(l,n) &
76 : + conjg(eigVecCoeffs%abcof(i,lmp,1,natom,2))*eigVecCoeffs%ccof(m,i,ilo,natom,1) * denCoeffsOffdiag%dulo21n(l,n) &
77 0 : + conjg(eigVecCoeffs%ccof(mp,i,ilo,natom,2))*eigVecCoeffs%abcof(i,lm,1,natom,1) * denCoeffsOffdiag%ulod21n(l,n))
78 : ENDDO
79 0 : DO ilop = 1, atoms%nlo(n)
80 0 : IF (atoms%llo(ilop,n).EQ.l) THEN
81 0 : DO i = 1,ne
82 : c_0 = c_0 + we(i) * denCoeffsOffdiag%uloulop21n(ilo,ilop,n) &
83 0 : *conjg(eigVecCoeffs%ccof(mp,i,ilop,natom,2)) *eigVecCoeffs%ccof(m ,i,ilo ,natom,1)
84 : ENDDO
85 : ENDIF
86 : ENDDO
87 0 : n_tmp(m,mp) = n_tmp(m,mp) + c_0
88 : ENDDO
89 : ENDDO
90 : ENDIF
91 : ENDDO
92 : !
93 : ! n_mmp should be rotated by D_mm' ; compare force_a21
94 : !
95 : !Note: This can be done only if the correct magnetic symmetries are
96 : !present. This is not the case at the moment (Jan 2020).
97 0 : n_mmp(:,:,i_u) = n_mmp(:,:,i_u) + conjg(symMMPmat(n_tmp,sym,natom,l,phase=.TRUE.)) * 1.0/atoms%neq(n)
98 : ENDDO ! sum over equivalent
99 : ENDDO ! loop over u parameters
100 :
101 0 : END SUBROUTINE n_mat21
102 : END MODULE m_nmat21
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