PROGRAM angles

c	Calculate angles and off plane distances

	REAL x(3,0:17), y(3), z(3), u(3), v(3), w(3)

	OPEN (unit=1, form='FORMATTED', status='OLD', file='ligands.diam',
	1	readonly)

	DO i = 1,3
	  READ (1, 1000) 
1000	  FORMAT (3f10.4)
	endDO

	DO i = 1,17
	  READ (1, 1000) (x(j,i), j=1,3)
	endDO
	CLOSE (unit=1)

	DO WHILE (.TRUE.)
	  READ (5, 1001, end=9) i1, i2, i3, i4, i5, i6, i7, i8
1001	  FORMAT (8i5)
	  DO i = 1,3
	    y(i) = x(i,i2) - x(i,i1)
	    z(i) = x(i,i4) - x(i,i3)
	    v(i) = x(i,i6) - x(i,i5)
	    w(i) = x(i,i8) - x(i,i7)
	  endDO

	  IF (i1 .LE. 0) GOTO 9

c	Do distances

	  IF (i3 .EQ. 0) THEN
	    sum = 0.
	    DO i = 1,3
	      sum = sum + y(i)*y(i)
	    endDO
	    dist = SQRT(sum)
	    WRITE (6, 1000) dist

c	Do angles

	  ELSE IF (i5 .EQ. 0) THEN
	    sum = 0.
	    sy = 0.
	    sz = 0.
	    DO i = 1,3
	      sum = sum + y(i)*z(i)
	      sy = sy + y(i)*y(i)
	      sz = sz + z(i)*z(i)
	    endDO
	    sz = SQRT(sz)
	    sy = SQRT(sy)
	    angle = ACOSD(sum/(sz*sy))
	    WRITE (6, 1000) angle

c	Do planes

	  ELSE
	    u(1) = y(2)*z(3) - z(2)*y(3)
	    u(2) = z(1)*y(3) - z(3)*y(1)
	    u(3) = y(1)*z(2) - z(1)*y(2)
	    sum = 0.
	    su = 0.
	    sv = 0.
	    DO i = 1,3
	      sum = sum + u(i)*v(i)
	      su = su + u(i)*u(i)
	      sv = sv + v(i)*v(i)
	    endDO
	    su = SQRT(su)
	    sv = SQRT(sv)
	    dist = sum/su
	    WRITE (6, 1000) dist
	    IF (i7 .NE. 0) THEN
	      sum = 0.
	      sw = 0.
	      DO i = 1,3
		sum = sum + u(i)*w(i)
		sw = sw + w(i)*w(i)
	      endDO
	      sw = SQRT(sw)
	      angle = 90. - ACOSD(sum/(su*sw))
	      WRITE (6, 1000) angle
	    endIF
	  endIF
	endDO

9	stop
	end