CreateInvBRR Subroutine

    SUBROUTINE CreateInvBRR(BRR, NBASIS)
        ! Create new INVBRR for the freezing process
        ! In:
        !    BRR(i)=j: orbital i is the j-th lowest in energy.
        !    nBasis: size of bais
        ! InvBRR is the inverse of BRR.  InvBRR(j)=i: the j-th lowest energy
        ! orbital corresponds to the i-th orbital in the original basis.
        INTEGER NBASIS
        INTEGER BRR(NBASIS), ierr, I, t
        character(*), parameter :: t_r = 'CreateInvBRR'

        IF (ASSOCIATED(INVBRR)) THEN
            CALL LogMemDealloc(t_r, tagINVBRR)
            DEallocate(INVBRR)
        end if
        allocate(INVBRR(NBASIS / 2), STAT=ierr)
        CALL LogMemAlloc('INVBRR', NBASIS / 2, 4, t_r, tagINVBRR, ierr)
        INVBRR(1:NBASIS / 2) = 0
        t = 0
        DO I = 2, NBASIS, 2
            t = t + 1
            INVBRR(BRR(I) / 2) = t
        end do
        RETURN

    END SUBROUTINE CreateInvBRR