SUBROUTINE RATIONALBASIS(
> BRAVAIS,RECBV,NBASIS,
X RBASIS)
implicit none
c#@# KKRtags: VORONOI geometry
c This subroutine rationalises the basis vectors
c by shifting them by appropriate lattice vectors
c so that they are closest to the origin.
c Input:
INTEGER NBASIS ! Number of basis vectors
REAL*8 BRAVAIS(3,3),RECBV(3,3) ! Bravais vectors of real and rec. lattice
! 1st index: xyz, second index: abc
c Input and output:
REAL*8 RBASIS(3,*) ! Basis vectors, to be changed on output.
c Local:
INTEGER IBASIS,IX,NB1,NB2,NB3
REAL*8 RLATT(3)
DO IBASIS = 1,NBASIS
c Find closest lattice point to basis site.
c Use reciprocal lattice vectors (remember they are given in units 2 pi/a).
c Remember, NINT(x) is the closest integer to x.
NB1 = NINT( RBASIS(1,IBASIS)*RECBV(1,1) +
& RBASIS(2,IBASIS)*RECBV(2,1) +
& RBASIS(3,IBASIS)*RECBV(3,1) )
NB2 = NINT( RBASIS(1,IBASIS)*RECBV(1,2) +
& RBASIS(2,IBASIS)*RECBV(2,2) +
& RBASIS(3,IBASIS)*RECBV(3,2) )
NB3 = NINT( RBASIS(1,IBASIS)*RECBV(1,3) +
& RBASIS(2,IBASIS)*RECBV(2,3) +
& RBASIS(3,IBASIS)*RECBV(3,3) )
c The closest lattice point is
c RLATTT = NB1 * Bravais1 + NB2 * Bravais2 + NB3 * Bravais3.
c Shift the basis site by this lattice vector.
DO IX = 1,3
RLATT(IX) = NB1 * BRAVAIS(IX,1) +
& NB2 * BRAVAIS(IX,2) + NB3 * BRAVAIS(IX,3)
RBASIS(IX,IBASIS) = RBASIS(IX,IBASIS) - RLATT(IX)
ENDDO
ENDDO
RETURN
END
