diff --git a/src/NWints/rel/int_rel_init.F b/src/NWints/rel/int_rel_init.F
new file mode 100644
index 0000000000..401c2144e8
--- /dev/null
+++ b/src/NWints/rel/int_rel_init.F
@@ -0,0 +1,151 @@
+c $Id: int_rel_init.F,v 1.1 1999-10-26 19:14:27 mg201 Exp $
+c:tex-% part of the internal API routines.
+c:tex-\subsection{int\_rel\_init}
+c:tex-This routine initializes the relativistic integrals.
+c:tex-
+c:tex-{\it Syntax:}
+c:tex-\begin{verbatim}
+      logical function int_rel_init(rtdb,nbas,basis)
+c:tex-\end{verbatim}
+      implicit none
+#include "nwc_const.fh"
+#include "apiP.fh"
+#include "basdeclsP.fh"
+#include "basP.fh"
+#include "bas.fh"
+#include "rel_nwc.fh"
+c::passed
+      integer rtdb, nbas, basis
+      dimension basis(nbas)
+c::local
+      integer geom
+      integer ibas,lbas,sbas,nucont,iucont,type,nprim,ngen,bastag
+      logical odum
+      character*255 basis_name,trans_name
+c
+      logical int_normalize
+      external int_normalize
+      logical  bas_name_exist_rtdb
+      external bas_name_exist_rtdb
+c
+      any_large = bas_name_exist_rtdb(rtdb,large_cmpt_name)
+      any_small = bas_name_exist_rtdb(rtdb,small_cmpt_name)
+      if (init_rel) then
+        write(6,*)' already called int_rel_init' 
+        call errquit('int_rel_init error',911)
+      end if
+      init_rel = .true.
+      do ibas = 1,nbas
+        odum = bas_name(basis(ibas),basis_name,trans_name)
+        if (basis_name(1:8) .eq. 'ao basis') go to 1
+      end do
+      call errquit('int_rel_init: could not find ao basis',911)
+    1 if (.not. bas_geom(basis(ibas), geom)) 
+     &    call errquit('int_rel_init: bas_geom?',0)
+c
+c   get small component basis set
+c
+      if (.not. bas_create(sc_bsh, 'small component'))
+     &    call errquit('int_rel_init: bas_create sc_bsh?', 0)
+      if (.not. bas_rtdb_load(rtdb, geom, sc_bsh, small_cmpt_name))
+     &    call errquit('int_rel_init: could not load small component',
+     &    0)
+      odum = int_normalize(sc_bsh)
+c
+c     check that small component basis matches beginning of ao basis
+c
+      lbas = basis(ibas) + BASIS_HANDLE_OFFSET
+      sbas = sc_bsh + BASIS_HANDLE_OFFSET
+      nucont = infbs_head(HEAD_NCONT,sbas)
+      do iucont = 1, nucont
+        type  = infbs_cont(CONT_TYPE, iucont,lbas)
+        if (type .lt. 0) call errquit (
+     &      'sp/spd shells illegal for relativistic basis',911)
+        nprim = infbs_cont(CONT_NPRIM,iucont,lbas) 
+        ngen  = infbs_cont(CONT_NGEN, iucont,lbas)
+        bastag  = infbs_cont(CONT_TAG, iucont,lbas)
+        if ((type.ne.infbs_cont(CONT_TYPE,iucont,sbas)) .or.
+     &      (nprim.ne.infbs_cont(CONT_NPRIM,iucont,sbas)) .or.
+     &      (ngen.ne.infbs_cont(CONT_NGEN, iucont,sbas)) .or.
+     &      (bastag.ne.infbs_cont(CONT_TAG, iucont,sbas))) 
+     &      call errquit (
+     &      'Small component basis does not match ao basis',911) 
+      end do
+c
+c     get large component basis set
+c
+      if (any_large) then
+        if (.not. bas_create(lc_bsh, large_cmpt_name))
+     $      call errquit('int_rel_init: bas_create lc_bsh?', 0)
+        if (.not.bas_rtdb_load(rtdb, geom, lc_bsh, large_cmpt_name))
+     &      call errquit(
+     &      'int_rel_init: could not load large component basis',0)
+        odum = int_normalize(lc_bsh)
+c
+c       check that large and small component basis sets match
+c
+        lbas = lc_bsh + BASIS_HANDLE_OFFSET
+        sbas = sc_bsh + BASIS_HANDLE_OFFSET
+        nucont = infbs_head(HEAD_NCONT,lbas)
+        if (nucont.ne.infbs_head(HEAD_NCONT,sbas)) call errquit
+     &      ('Large and small component bases do not match',911)
+        do iucont = 1, nucont
+          type  = infbs_cont(CONT_TYPE, iucont,lbas)
+          nprim = infbs_cont(CONT_NPRIM,iucont,lbas) 
+          ngen  = infbs_cont(CONT_NGEN, iucont,lbas)
+          bastag  = infbs_cont(CONT_TAG, iucont,lbas)
+          if ((type.ne.infbs_cont(CONT_TYPE,iucont,sbas)) .or.
+     &        (nprim.ne.infbs_cont(CONT_NPRIM,iucont,sbas)) .or.
+     &        (ngen.ne.infbs_cont(CONT_NGEN, iucont,sbas)) .or.
+     &        (bastag.ne.infbs_cont(CONT_TAG, iucont,sbas))) 
+     &        call errquit (
+     &        'Large and small component bases do not match',911) 
+        end do
+c
+c  this next line is only for the one-electron approximation. It must
+c  be removed when the two-electron code is added.
+c
+      else
+        call errquit('Must have both large and small component',911)
+      end if
+c
+      call rel_init_con
+      int_rel_init = .true.
+c
+      end
+*
+      subroutine int_rel_term
+      implicit none
+#include "bas.fh"
+#include "apiP.fh"
+#include "rel_nwc.fh"
+c
+      if (lc_bsh .ne. -1) then
+        if (.not. bas_destroy(lc_bsh)) call errquit(
+     &      'int_rel_terminate: failed to destroy large component basis'
+     &      ,0)
+        lc_bsh = -1
+      end if
+      if (sc_bsh .ne. -1) then
+        if (.not. bas_destroy(sc_bsh)) call errquit(
+     &      'int_rel_terminate: failed to destroy small component basis'
+     &      ,0)
+        sc_bsh = -1
+      endif
+      any_rel = .false.
+      any_large = .false.
+      any_small = .false.
+      init_rel = .false.
+c
+      end
+
+      block data rel_init_bd
+c
+c   Block data for relativistic integrals
+c
+#include "rel_nwc.fh"
+      data init_rel /.false./
+      data small_cmpt_name/'small component'/
+      data large_cmpt_name/'large component'/
+      end
+
diff --git a/src/NWints/rel/rel_nwc.fh b/src/NWints/rel/rel_nwc.fh
new file mode 100644
index 0000000000..99161d9c3a
--- /dev/null
+++ b/src/NWints/rel/rel_nwc.fh
@@ -0,0 +1,6 @@
+* $Id: rel_nwc.fh,v 1.1 1999-10-26 19:16:50 mg201 Exp $
+      logical init_rel        ! relativistic integral initialization
+      character*32 small_cmpt_name,large_cmpt_name
+c
+      common /c_rel_nwc/ init_rel,small_cmpt_name,large_cmpt_name
+