      subroutine fixrhs(w,d,den,e,ntsiz,pop,vrt,nocc,nvrt,ispin,iuhf)
C
cjp used to prepare from T1 RHS the <j,b|HexpT|0> term for 4.28
cjp NOTE: this routine can be called only with ispin=1,2
cjp
C
      IMPLICIT DOUBLE PRECISION (A-H,O-Z)
      LOGICAL LINCC,CICALC
      INTEGER DIRPRD,POP,VRT
cjp
      integer itrue,iatrue
      DIMENSION W(NTSIZ),E(NOCC+NVRT),
     &          D(NTSIZ),DEN(NTSIZ),POP(8),VRT(8)
      COMMON /MACHSP/ IINTLN,IFLTLN,IINTFP,IALONE,IBITWD
      COMMON /SYMINF/ NSTART,NIRREP,IRREPA(255),IRREPB(255),
     &                DIRPRD(8,8)
      COMMON /FLAGS/ IFLAGS(100)
      COMMON /LINEAR/ LINCC,CICALC
      COMMON /CORENG/ ELAST
C
      EQUIVALENCE(IFLAGS(2),METHOD)
C
cjp


cjp
cjp data for multireference state specific Brillouin-Wigner CC method
cjp coded by Jiri Pittner 1998-2000
cjp
      logical isbwcc,masik,isactive,bwgossip,useeq429,scfrefread
      logical bwwarning
      character*256 bwwarntext
      real*8 ecorrbw0,ecorrbw,epsilon0,fockcontr,denomblow,fockcd
      real*8 heff,heffevalr,heffevali,heffevecl,heffevecr,hdiagcontr
      real*8 fock2elcontr,enerscf,hcore,lambdahomotop,hfakt,diishonset
      real*8 fock2elcontr0,enerscf0,cbwstate,totmaxdenom,heffevecrold
      real*8 intruder,hfaktmax
      integer maxorb,maxref,nref, iref, iocc,iocc0
      integer iphnum,invpnum,invhnum,nbwstates,ibwstate
      integer ibwconvg,internfrom,internto,internnum,internindex
      integer ibwpass
      integer nactive,numactive,ihubaccorr,ihomotop
      integer internfrom1,internto1,internindex1,internnum1
      integer ihefferank, iheffefrom, iheffeto, iheffespin, maxexcit
      integer correctiontype
      integer maxbwwarnings, nproc, myproc
c
      parameter(maxorb=512,maxref=32,maxexcit=9,maxbwwarnings=10)
c      NOTE!!! change of maxorb parameter requires format change
c              and character* change in bwread routine!!!
      parameter(denomblow=1d250)
c

cjp common has been splitted in order to avoid problems
cjp with padding on different 32 and 64 bit architectures

      common/bwccint/isbwcc, masik, nref, iref,iocc(maxorb,maxref,2),
     +     iphnum(maxorb,maxref,2),invpnum(maxorb,maxref,2),
     +     invhnum(maxorb,maxref,2),
     +     isactive(maxorb,2),nbwstates,ibwstate(maxref+1),
     +     internfrom(maxref*(maxref-1)/2,maxref,3),
     +     internto(maxref*(maxref-1)/2,maxref,3),
     +     internindex(maxref*(maxref-1)/2,maxref,3),
     +     internnum(maxref,3),
     +     internfrom1(maxref*(maxref-1)/2,maxref,2),
     +     internto1(maxref*(maxref-1)/2,maxref,2),
     +     internindex1(maxref*(maxref-1)/2,maxref,2),
     +     internnum1(maxref,2),
     +     ibwpass,ibwconvg(maxref),bwgossip,useeq429,
     +     nactive(2),numactive(maxorb,2),ihubaccorr, ihomotop,
     +     iocc0(maxorb,2),scfrefread,
     +     ihefferank(maxref,maxref),iheffefrom(maxexcit,maxref,maxref),
     +     iheffeto(maxexcit,maxref,maxref),
     +     iheffespin(maxexcit,maxref,maxref),
     +     correctiontype,bwwarning(maxbwwarnings),
     +     bwwarntext(maxbwwarnings),nproc,myproc

      common/bwccreal/ecorrbw,epsilon0,cbwstate(maxref+1),
     +     fockcontr(maxorb*(maxorb+1)/2,2),fockcd(maxorb,maxref,2),
     +     heff(maxref,maxref),heffevalr(maxref),heffevali(maxref),
     +     heffevecl(maxref,maxref),heffevecr(maxref,maxref),
     +     hdiagcontr(maxref), fock2elcontr(maxorb,2),
     +     enerscf(maxref), hcore(maxorb,2),
     +     lambdahomotop,hfakt,diishonset,enerscf0,
     +     fock2elcontr0(maxorb,2),ecorrbw0,totmaxdenom,
     +     heffevecrold(maxref,maxref),intruder,hfaktmax

c
c
cjp BRIEF DESCRIPTION OF VARIABLES INTRODUCED FOR THE MR-BWCC ROUTINES
cjp IN FACT, A LOT OF THAT COULD BE USEFUL FOR ANY HILBERT-SPACE MR-CC
c
c
c isbwcc ... flag for doing bwcc calculation
c maxbwwarnings, bwwarning, bwwarntext ... serious warnings will be
c    summarized at the end of xvcc output for the user's' convenience
c ihefferank(jref,iref) ... degree of excitation between jref and iref
c iheffefrom(maxexcit,jref,iref) , iheffeto, iheffespin ... list of
c    indices of that excitation, sorted according to spin and then the
c    indices, numbers stored are defined as effective particle-hole
c    indices of reference iref
c ihomotop ... whether to use homotopic transition to the
c    size-extensivity correction, after which iteration (if .ne.0)
c lambdahomotop scaling factor of the geometrical series of
c    lambda 1->0 transition
c hfakt ... current value of the homotopy parameter
c hfaktmax ... maximal homotopy parameter allowed to consider cc
c    equations converged
c diishonset ... at which value of hfact restart diis convergence acceleration
c masik ... prepare sorted integral file for the program by Masik and stop
c nref ... number of reference configurations
c iref ... current reference configuration and fermi vacuum
c bwgossip ... switch on debugging output
c ibwpass ... routines like newt2 have to be splitted in two passes -
c    construction of Heff and amplitude update after heff is diagonalized
c    for backw. compatibility, instead of introducing a new routine
c    the same routine does different things being called twice with
c    different ibwpass value
c ecorrbw ... correlation energy from BWCC - Heff(iref,iref) ...
c    denominator correction
c ecorrbw0 .... ecorrbw, but not scaled by the homotopic factor hfact
c denomblow ... huge number to cause division underflow - used for
c    zeroing out the internal amplitudes automatically
c nactive(spin): total count of active spinorbitals
c numactive(i=1..nactive,spin): number of i-th active spinorbital
c    in sequential numbering
c isactive(maxorb,spin): belongs given orbital to the active space?
c    for RHF, the beta ones must be initialized to be identical with alpha ones
c iocc(maxorb,1..nref,spin): defines the nref reference configurations
c    for both RHF and UHF:  iocc(i,iref,spin)=0 or 1
c iphnum(orbital no, iref, spin): gives the effective number of orbital
c    (both particle and hole ones are counted starting from 1)
c invpnum(eff.p.orb.,iref,spin): gives true orbital no. from the
c    effective particle one
c invhnum(eff.h.orb.,iref,spin): gives true orbital no. from the
c    effective hole one
c    all these three ones must be in RHF case initialised to be equal in the
c    alpha and beta parts to keep the code unique and simple
c internfrom(sequence counter n,iref,ispin) is for the ab spin case, the
c    other ones have to be iuhf-indexed
c    internfrom, internto: they are first and second index of n-th internal
c    excitation when processing reference given by second index to the array
c
c internindex(sequence counter,iref,ispin) is the position of
c    corresponding denominator in the denominator list
c internnum(iref,ispin) - number of internal excitation in that
c    category = max sequence counter here ispin=1,2,3 for AA,BB,AB
c internfrom1 etc. are analogous quantities for monoexcitations, here
c    ispin =1,2 note for later: all intern.... quantities are irrep-specific!
c fockcontr(findex(i,j),ispin) ... addition to the fock matrix of
c    reference no.1 to obtain the fock matrix of current reference
c    (fermi vacuum)
c fockcd(i,iref,ispin) ... diagonal part of that correction for ref. no. iref.
c hcore(i,ispin) ... one electron diagonal hamiltonian elements
c fock2elcontr(i,ispin) ... 2el contribution to the diagonal fock element
c    used temporarily
c hdiagcontr(iref) ... contribution of differences of HF energies of
c    different Fermi vacua to diagonal Heff elements
c enerscf(iref) ... HF energy of iref-th fermi vacuum
c ihubaccorr ... =1 ... calculate the size extenzivity correction for BWCC
c                =2,3 ... second and third pass of that calculation
c iocc0(maxorb,2) ... like iocc, but for dummy reference configuration
c    corresponding to SCF WF
c fock2elcontr0(maxorb,2) ... like fock2elcontr0 but for dummy reference
c    configuration
c enerscf0 ... like enerscf, but for dummy reference config
c scfrefread ... tells to bwprep that SCF reference has been read from input
c    and should not be generated automatically from nocc(ispin)
c nbwstates ... how many states to average
c ibwstates(1..nbwstates),cbwstates() ... their numbers and coefficients
c correctiontype ... 0=DC,L T2 term is removed/scaled, 1=DC/L term is not
c    removed/scaled
c totmaxdenom ... max 1/denom found for given reference's' fermi vacuum -
c    as indication of possible intruder problem
c intruder ... limit of 1/denom to be considered intruder and its
c    amplitude zeroed
c for parallelization
c nproc ... number of processors (counted from 1)
c myproc ... number of the processor currently executing the code
c    (counted from 1)


C
C     GET ORBITAL ENERGIES FROM DISK
C
      if(ispin.eq.1.or.iuhf.eq.0)then
       CALL GETREC(20,'JOBARC','SCFEVALA',IINTFP*(NOCC + NVRT),
     &             E)
      ELSE
       CALL GETREC(20,'JOBARC','SCFEVALB',IINTFP*(NOCC + NVRT),
     &             E)
      ENDIF
cjp fix diagonal fock elements
      if(isbwcc) then
        do i=1,nocc+nvrt
          e(i)=e(i)+fockcd(i,iref,ispin)
        enddo
      endif
C
C     LOOP OVER IRREPS
C
      IND=0
      INDI=0
      INDA0=0
C
      DO 100 IRREP=1,NIRREP
C
      NOCCI=POP(IRREP)
      NVRTI=VRT(IRREP)
C
cjp
cjp HERE DO NOT identify the internal amplitudes
cjp the following is also completely wrong if symmetry is on
      DO  10 I=1,NOCCI
      INDI=INDI+1
      INDA=INDA0
      DO  10 IA=1,NVRTI
      INDA=INDA+1
      IND=IND+1
           itrue=invhnum(indi,iref,ispin)
           iatrue=invpnum(inda,iref,ispin)
           den(ind)=e(itrue)-e(iatrue)
cjp correction 2: put just LHS of BWCC T1, for internal one keep just the RHS as is
           if(correctiontype.eq.2.and.
     & .not.(isactive(itrue,ispin).and.isactive(iatrue,ispin))) then
           w(ind)=ecorrbw0*d(ind)
           endif
           if(bwgossip.and.correctiontype.eq.2)
     &   write(6,*)'fixrhs:c=2 : ind, ispin, iref,w(ind)'
     &              ,ind, ispin, iref,w(ind)
   10 CONTINUE
      INDA0=INDA0+NVRTI
100   CONTINUE
C
C    compute addition to the rhs of RSCC to get the <...> elements for 4.28
C
cjp use old, internal-zeroed, amplitudes
cjp this is the correct version
c
       if(correctiontype.le.1) then
cjp
cjp correction type =1 ... build full <> term from current amplitudes and denominators
cjp at convergence scaled to RSCC, this gives zeros except internal excitations
cjp when it is Heff element
cjp
      DO  I=1,NTSIZ
      w(i)=w(i)-d(i)*den(i)
      enddo
c
      endif
cjp correctiontype.eq.2 has been done above already

C
      RETURN
      END
