C Minkowski spacetime
C $Header$

#include "cctk.h"

      subroutine Exact__Minkowski(
     $     x, y, z, t,
     $     gdtt, gdtx, gdty, gdtz, 
     $     gdxx, gdyy, gdzz, gdxy, gdyz, gdzx,
     $     gutt, gutx, guty, gutz, 
     $     guxx, guyy, guzz, guxy, guyz, guzx,
     $     psi, Tmunu_flag)

      implicit none

c input arguments
      CCTK_DECLARE(CCTK_REAL, x,)
      CCTK_DECLARE(CCTK_REAL, y,)
      CCTK_DECLARE(CCTK_REAL, z,)
      CCTK_DECLARE(CCTK_REAL, t,)

c output arguments
      CCTK_REAL gdtt, gdtx, gdty, gdtz, 
     $       gdxx, gdyy, gdzz, gdxy, gdyz, gdzx,
     $       gutt, gutx, guty, gutz, 
     $       guxx, guyy, guzz, guxy, guyz, guzx
      CCTK_DECLARE(CCTK_REAL, psi,)
      LOGICAL   Tmunu_flag

C This is a vacuum spacetime with no cosmological constant
      Tmunu_flag = .false.

      gdtt = -1.d0 
      gdtx = 0.d0 
      gdty = 0.d0 
      gdtz = 0.d0 
      gdxx = 1.d0 
      gdyy = 1.d0 
      gdzz = 1.d0 
      gdxy = 0.d0 
      gdyz = 0.d0 
      gdzx = 0.d0

      gutt = -1.d0 
      gutx = 0.d0 
      guty = 0.d0 
      gutz = 0.d0 
      guxx = 1.d0 
      guyy = 1.d0 
      guzz = 1.d0 
      guxy = 0.d0 
      guyz = 0.d0 
      guzx = 0.d0

      return
      end