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rg_MCb_rlzn.F90
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rg_MCb_rlzn.F90
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subroutine rg_MCb_rlzn( NC, NX, B, x1,x2,x3 , SS )
use renorm_utils, only : blockrg , s4x3ftn
implicit none
real, intent(in) :: x1,x2,x3
integer, intent(in) :: NX,NC,B
real, intent(out) :: SS(4,3)
!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
integer :: a,c,d,e,f,g,h,i,j,k,l,m,n,o,p,s
integer :: aa,bb,cc,dd
integer :: i1,i2,i3,i4,Nspin,Nconf, ii,jj,kk
integer :: NN,NNN,NNNN
real :: Econfig, boltzmann_wgt,w1,w2,w3,ZZZ,ZZp,mm1,mm2,DEE,zzz2,mm1x
integer :: flipspin,ncorr,isweep
integer :: CCC(0:Nx+1,0:Nx+1), Bccc( 0:nx/b+1 , 0:nx/b+1 )
real :: Delta_Ex( NC ), Delta_Ep( NC ), Energy(NC)
real :: MeanMag(NC),ran1,ran2,ran3
real :: corr(NX,NX,NX,NX),corrv( 0:NX/2 ),corr3v(3)
integer, allocatable :: seed(:)
integer :: clock,countv(0:NX/2)
real :: Ranu( NX,NX ),mc1(NC),mc2(NC),mc3(NC),DEEc,DEEx,E_init,E_final
integer :: IX(NC), JY(NC), iflip, jflip,nxb, ip, jp
real :: S1,S2,S3,S11,S12,S13,S21,S22,S23,S31,S32,S33,DEE1,DEE2,DEE3
logical :: llrenorm
!! FUNCTIONS
!!real :: energy_ccc
!======================================================
! Input coupling coefficients are assumed to be in the
! form K = -J/(kb*T) where J's come from Hamiltonian
!
! H = SUM_(ij=NN) -J*S_i*S_j
!
! Critical value: K=0.4407... (analytical, Onsager).
! Note negative sign in front of J. Positive J then
! means *lower* Energy with aligned spins.
!======================================================
isweep=0
S1=0.
S2=0.
S3=0.
S11=0.
S12=0.
S13=0.
S21=0.
S22=0.
S23=0.
S31=0.
S32=0.
S33=0.
nxb=nx/b
call random_seed(size = n)
allocate(seed(n))
call random_seed(get=seed)
!write(*,*) "T per site=",1./X1," K1=",X1
! SYSTEM_CLOCK call results in a different sequence each time:
CALL SYSTEM_CLOCK(COUNT=clock)
seed = clock + 37 * (/ (i - 1, i = 1, n) /)
call random_seed(put=seed)
CALL RANDOM_NUMBER(ranu)
mc1=0.
mc3=0.
ccc=0.
!=============================
! Initial Spin configuration
!=============================
#if 0
!random spins
ccc(:,:)=0
where(ranu >=0.5)
ccc(1:NX,1:NX)=1
elsewhere
ccc(1:NX,1:NX)=-1
end where
#endif
#if 0
! cold start
ccc(:,:)=1
#endif
#if 0
! Checker board
ccc(:,:)=1
do j=1,NX,2
do i=1,NX,2
ccc(i,j)=-1
end do
end do
#endif
#if 0
! "Continent"
ccc(:,:)=1
do j=1,NX
do i=1,NX/2
ccc(i,j)=-1
end do
end do
#endif
#if 1
! Stripes
ccc(:,:)=1
do i=1,NX-4,4
ccc(i:i+2,:)=-1
end do
#endif
#if 1
! == Periodic BCs ===
ccc( 1:NX , NX+1 ) = ccc( 1:NX , 1 )
ccc( 1:NX , 0 ) = ccc( 1:NX , NX )
ccc( NX+1 , 1:NX ) = ccc( 1 , 1:NX )
ccc( 0 , 1:NX ) = ccc( NX , 1:NX )
ccc( NX+1 , Nx+1 ) = ccc( 1 , 1 )
ccc( 0 , Nx+1 ) = ccc( NX , 1 )
ccc( Nx+1, 0 ) = ccc( 1 , NX )
ccc( 0 , 0 ) = ccc( NX , NX )
#endif
!====================================
! Energy of initial spin configuration
!=====================================
mm1=0.
DEE=0.
do kk=1,NC-1
#if 1
call random_number( ran1 )
jy(kk) = INT( ran1*(NX))+1
call random_number( ran2 )
ix(kk) = INT( ran2*(NX))+1
! Now flip spins
!===============
iflip = IX(kk)
jflip = JY(kk)
#endif
#if 0
ysweep: do jflip=1,NX
xsweep: do iflip=1,NX
#endif
#if 1
ip=iflip
jp=jflip
DEE1 = 2 * X1 * CCC( ip, jp ) * ( CCC( ip+1,jp )+CCC(ip,jp+1)+CCC(ip-1,jp)+CCC(ip,jp-1) )
! NNN contribution
DEE2 = 2 * X2 * CCC( ip, jp ) * ( CCC(ip+1,jp+1) + CCC(ip+1,jp-1)+CCC(ip-1,jp+1)+CCC(ip-1,jp-1) )
! QUAD/NNNN contribution
DEE3 = 2 * X3 * CCC( ip, jp ) * &
( CCC( ip-1, jp )*CCC( ip-1,jp+1 )*CCC( ip,jp+1 ) & ! |-
+ CCC( ip, jp+1 )*CCC( ip+1,jp+1 )*CCC( ip+1,jp ) & ! -|
+ CCC( ip+1,jp )*CCC( ip+1,jp-1 )*CCC( ip,jp-1 ) & ! _|
+ CCC( ip,jp-1 )*CCC( ip-1,jp-1 )*CCC( ip-1,jp ) ) ! |_
DEE = DEE1 + DEE2 + DEE3
#endif
#if 0
DEE = 2 * X1 * CCC( iflip, jflip ) * &
( CCC( iflip+1, jflip ) &
+ CCC( iflip-1, jflip ) &
+ CCC( iflip , jflip+1) &
+ CCC( iflip , jflip-1) )
! NNN contribution
DEE = DEE + 2 * X2 * CCC( iflip, jflip ) * &
( CCC( iflip+1, jflip+1 ) &
+ CCC( iflip-1, jflip+1 ) &
+ CCC( iflip+1, jflip-1) &
+ CCC( iflip-1, jflip-1) )
! QUAD/NNNN contribution
DEE = DEE + 2 * X3 * CCC( iflip, jflip ) * &
( CCC( iflip+1, jflip+1 )*CCC( iflip,jflip+1 )*CCC( iflip+1,jflip ) & !ne
+ CCC( iflip , jflip+1 )*CCC( iflip-1,jflip+1)*CCC( iflip-1,jflip ) & !nw
+ CCC( iflip-1, jflip )*CCC( iflip-1,jflip-1)*CCC( iflip,jflip-1 ) & !sw
+ CCC( iflip , jflip-1 )*CCC( iflip+1,jflip-1)*CCC( iflip+1,jflip ) ) !se
#endif
call random_number( ran3 )
if ( ( DEE<0.) .OR. ( ran3 < exp(-DEE) ) ) then
CCC( iflip, jflip ) = -CCC( iflip, jflip )
DEEx=DEE
else
DEEx=0.
end if
!end do xsweep
!end do ysweep
#if 1
! == Periodic BCs ===
ccc( 1:NX , NX+1) = ccc( 1:NX , 1 )
ccc( 1:NX , 0 ) = ccc( 1:NX , NX )
ccc( NX+1 , 1:NX) = ccc( 1 , 1:NX )
ccc( 0 , 1:NX) = ccc( NX , 1:NX )
ccc( NX+1 , Nx+1) = ccc( 1 , 1 )
ccc( 0 , Nx+1) = ccc( NX , 1 )
ccc( Nx+1, 0 ) = ccc( 1 , NX )
ccc( 0 , 0 ) = ccc( NX , NX )
#endif
if (b >=2 ) then
bccc = blockrg( ccc, nx, b )
else
bccc(:,:)=ccc(:,:)
end if
!if ( mod(kk,100*nx*nx)==0 ) write(2011) ccc,bccc,kk
if (KK >= NC/3 ) then
! Now calculate even <spin-spin> terms for config kk
NN = 0.
NNN = 0.
NNNN = 0.
do j=1,NXb
do i=1,NXb
aa = bccc(i,j)
bb = bccc(i+1,j)
cc = bccc(i,j+1)
dd = bccc(i+1,j+1)
NN = NN + aa*bb + aa*cc
NNN = NNN + aa*dd + bb*cc
NNNN = NNNN + aa*bb*cc*dd
end do
end do
S1 = S1 + dble( NN )
S2 = S2 + dble( NNN )
S3 = S3 + dble( NNNN )
S11 = S11 + dble( NN * NN )
S21 = S21 + dble( NNN * NN )
S31 = S31 + dble( NNNN * NN )
S12 = S12 + dble( NN * NNN )
S22 = S22 + dble( NNN * NNN )
S32 = S32 + dble( NNNN * NNN )
S13 = S13 + dble( NN * NNNN )
S23 = S23 + dble( NNN * NNNN )
S33 = S33 + dble( NNNN * NNNN )
isweep= isweep+1
ZZZ=dble( isweep )
endif
end do
S1=S1/ZZZ
S2=S2/ZZZ
S3=S3/ZZZ
SS(1,1) = S11 / ZZZ - S1*S1
SS(1,2) = S12 / ZZZ - S1*S2
SS(1,3) = S13 / ZZZ - S1*S3
SS(2,1) = S21 / ZZZ - S2*S1
SS(2,2) = S22 / ZZZ - S2*S2
SS(2,3) = S23 / ZZZ - S2*S3
SS(3,1) = S31 / ZZZ - S3*S1
SS(3,2) = S32 / ZZZ - S3*S2
SS(3,3) = S33 / ZZZ - S3*S3
SS(4,1) = S1
SS(4,2) = S2
SS(4,3) = S3
end subroutine rg_MCb_rlzn