PROGRAM           nearby

c     Reads list of peaks (or holes) and tells which atoms are near
c     Only sees if near potential H-bond partner unless crit<0

      PARAMETER         NDIM = 30000

      REAL              x(NDIM), y(NDIM), z(NDIM), cell(6)
      CHARACTER*15      label(NDIM)
      CHARACTER*60      filename
      LOGICAL           flag

c     Read distance criterion

      WRITE (6, 1000) 'Enter distance criterion:'
      READ (5, 1001) crit
      WRITE (6, 1001) crit
      flag = crit.GT.0
      crit = crit*crit

c     Read coordinates

      WRITE (6, 1000) 'Enter filename for Diamond file:'
1000  FORMAT (a)
      READ (5, 1000) filename
      WRITE (6, 1000) filename
      OPEN (unit=1, form='FORMATTED', status='OLD', file=filename,
     1     readonly)

      READ (1, 2001) cell
2001  FORMAT (6F10.3)
      sinb = SIND(cell(5))
      cosb = COSD(cell(5))
      WRITE (6, 2001) cell
      READ (1, 1001)
      READ (1, 1001)

      num = 1
      nn = 1
      DO WHILE (.TRUE.)
1       READ (1, 1001, end=99, err=1) x(nn), y(nn), z(nn), b, 
     1     itype, mres, n, wt, label(nn)
1001       FORMAT (4f10.5, 3i5, f9.5, a)
        nn = nn + 1
      endDO
99    num = nn-1
      CLOSE (unit=1)

c     Loop through list and find atoms near by

      WRITE (6, 1000) 'Enter filename for input list:'
      READ (5, 1000) filename
      WRITE (6, 1000) filename
      OPEN (unit=2, form='FORMATTED', status='OLD', file=filename,
     1     readonly)

      WRITE (6, 1000) 'Enter filename for output list:'
      READ (5, 1000) filename
      WRITE (6, 1000) filename
      OPEN (unit=3, form='FORMATTED', file=filename, status='UNKNOWN')

      DO WHILE (.TRUE.)
        READ (2, 1002, end=999) peak, xp, yp, zp
1002    FORMAT (f15.4, 15x, 3f10.3)

        dmin = 1.e10
        DO n = 1, num
          xx = x(n) - xp
          yy = y(n) - yp
          zz = z(n) - zp
          zz = zz + xx*cosb
          xx = xx*sinb
          d = xx*xx + yy*yy + zz*zz
          IF (d .LT. dmin) THEN
            dmin = d
            ijk = (n)
          endIF
        endDO

        IF (dmin .GE. ABS(crit)) GOTO 100	! have nearest atom
	IF (flag .AND. label(ijk)(12:13) .NE. 'FE' .AND.
	1	label(ijk)(12:12) .NE. 'O' .AND. 
	2	label(ijk)(12:12) .NE. 'N') 
	3	GOTO 100

	WRITE (3, 1003) peak, label(ijk), xp, yp, zp, SQRT(dmin)
1003    FORMAT (f15.4, a15, 4f10.3)

100     continue
      endDO

999   CLOSE (unit=2)
      CLOSE (unit=3)

      end