C ************************************************************************
SUBROUTINE LATTIX12(LINTERFACE,ALATC,BRAVAIS,RECBV,RR,NR,VOLUC)
c#@# KKRtags: VORONOI geometry
C ************************************************************************
C LATTIX99 GENERATES THE REAL SPACE AND RECIPROCAL LATTICES.
C BRAVAIS(I,J) ARE BASIS VECTORS, WITH I=X,Y,Z AND J=A,B,C.
C RECIPROCAL SPACE VECTORS ARE IN UNITS OF 2*PI/A0.
C RR ARE THE DIRECT SPACE VECTORS.
C NR+1 IS THE NUMBER OF DIRECT SPACE VECTORS CREATED
C (STRUCTURE DEPENDENT OUTPUT).
C ************************************************************************
C
implicit none
INCLUDE 'inc.geometry'
C
LOGICAL LINTERFACE
C
INTEGER
+ NR, ! number of real space vectors
+ I,J,IER
C
REAL*8
+ VOLUC,ALATC,
+ DET,PI,TPI,DDET33
C
REAL*8
+ BRAVAIS(3,3), ! Real space bravais vectors. Read in normalized to
c ! altc.
+ RECBV(3,3), ! RECIPROCAL BASIS IN 2*PI/A
+ RR(3,0:NRD)
c
c
EXTERNAL CROSPR,SPATPR,DDET33
c
c
c ------------------------------------------------------------------------
PI = 4.D0*DATAN(1.D0)
c
c
c Generate the reciprocal lattice unit-vectors, and calculate the unit-cell
c volume in units au**3.
c Initialize:
DO I=1,3
DO J=1,3
RECBV(J,I)=0.D0
ENDDO
ENDDO
c Calculate:
IF (.NOT.(LINTERFACE)) THEN
c 1. 3-dimentional case
DET=DDET33(BRAVAIS)
IF (DET.EQ.0.D0) THEN
WRITE(*,*) '3-d Bravais vectors are linearly dependent:'
WRITE(*,9000) ((BRAVAIS(J,I),J=1,3),I=1,3)
STOP 'LATTIX99: 3-d Bravais vectors are
+ linearly dependent'
END IF
CALL CROSPR(BRAVAIS(1,2),BRAVAIS(1,3),RECBV(1,1))
CALL CROSPR(BRAVAIS(1,3),BRAVAIS(1,1),RECBV(1,2))
CALL CROSPR(BRAVAIS(1,1),BRAVAIS(1,2),RECBV(1,3))
CALL SPATPR(BRAVAIS(1,2),BRAVAIS(1,3),BRAVAIS(1,1),VOLUC)
VOLUC= ABS(VOLUC)
DO I=1,3
DO J=1,3
RECBV(J,I)=RECBV(J,I)/VOLUC
ENDDO
ENDDO
ELSE
c 2. 2-dimentional case
DET=BRAVAIS(1,1)*BRAVAIS(2,2)-BRAVAIS(1,2)*BRAVAIS(2,1)
IF (ABS(DET).LT.1.D-8) THEN
WRITE(*,*) '2-d Bravais vectors are linearly dependent:'
WRITE(*,9000) ((BRAVAIS(J,I),J=1,3),I=1,3)
STOP 'LATTIX99: 2-d Bravais vectors are linearly dependent'
ENDIF
RECBV(1,1)= BRAVAIS(2,2)/DET
RECBV(2,1)= -BRAVAIS(1,2)/DET
RECBV(1,2)= -BRAVAIS(2,1)/DET
RECBV(2,2)= BRAVAIS(1,1)/DET
VOLUC= ABS(DET)
ENDIF
c Reciprocal lattice unit-vectors and unit-cell volume calculated.
c
write(6,*) 'True basis vectors (not normalized):'
write(6,9000) ((BRAVAIS(J,I)*ALATC,J=1,3),I=1,3)
write(6,*) 'Reciprocal lattice vectors, in units 2pi/a:'
write(6,9000) ((RECBV(J,I),J=1,3),I=1,3)
c
c ---> now generate the real-space lattice vectors for the cluster generation:
c The parameter LATT is not used in RRGEN
CALL RRGEN(BRAVAIS,ALATC,LINTERFACE,RR,NR)
c
c ---> test on volume unit cell:
c
IF (VOLUC.LT.1.0D-5) THEN
WRITE(6,909) VOLUC
909 FORMAT(//' STOP. VOLUC IN LATTIX99 IS TOO SMALL:',
+ ' VOLUC= ',D13.4)
STOP
END IF
C
1000 FORMAT(i4,3F15.10)
1001 FORMAT( ' vol,voluc: ',2F10.4)
9000 FORMAT(3F14.8/3F14.8/3F14.8)
9010 FORMAT('Caution: the two-dimentional Bravais vectors have also',/,
& 'a z-component. It will be set to zero.')
RETURN
END
