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c     ##  COPYRIGHT (C)  1992  by  Jay William Ponder  ##
c     ##              All Rights Reserved              ##
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c     ##                                                            ##
c     ##  module boxes  --  periodic boundary condition parameters  ##
c     ##                                                            ##
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c     xbox        length of a-axis of periodic box in Angstroms
c     ybox        length of b-axis of periodic box in Angstroms
c     zbox        length of c-axis of periodic box in Angstroms
c     alpha       angle between b- and c-axes of box in degrees
c     beta        angle between a- and c-axes of box in degrees
c     gamma       angle between a- and b-axes of box in degrees
c     xbox2       half of the a-axis length of periodic box
c     ybox2       half of the b-axis length of periodic box
c     zbox2       half of the c-axis length of periodic box
c     box34       three-fourths axis length of truncated octahedron
c     volbox      volume in Ang**3 of the periodic box
c     alpha_sin   sine of the alpha periodic box angle
c     alpha_cos   cosine of the alpha periodic box angle
c     beta_sin    sine of the beta periodic box angle
c     beta_cos    cosine of the beta periodic box angle
c     gamma_sin   sine of the gamma periodic box angle
c     gamma_cos   cosine of the gamma periodic box angle
c     beta_term   term used in generating triclinic box
c     gamma_term  term used in generating triclinic box
c     lvec        real space lattice vectors as matrix rows
c     recip       reciprocal lattice vectors as matrix columns
c     orthogonal  flag to mark periodic box as orthogonal
c     monoclinic  flag to mark periodic box as monoclinic
c     triclinic   flag to mark periodic box as triclinic
c     octahedron  flag to mark box as truncated octahedron
c     dodecadron  flag to mark box as rhombic dodecahedron
c     nonprism    flag to mark octahedron or dodecahedron
c     nosymm      flag to mark use or lack of lattice symmetry
c     spacegrp    space group symbol for the unit cell type
c
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      module boxes
      implicit none
      real*8 xbox,ybox,zbox
      real*8 alpha,beta,gamma
      real*8 xbox2,ybox2,zbox2
      real*8 box34,volbox
      real*8 alpha_sin
      real*8 alpha_cos
      real*8 beta_sin
      real*8 beta_cos
      real*8 gamma_sin
      real*8 gamma_cos
      real*8 beta_term
      real*8 gamma_term
      real*8 lvec(3,3)
      real*8 recip(3,3)
      logical orthogonal
      logical monoclinic
      logical triclinic
      logical octahedron
      logical dodecadron
      logical nonprism
      logical nosymm
      character*10 spacegrp
      save
      end