Index

Core dictionary version 3.3.0

_geom_angle.value

Definition:

   
    The value of the angle defined by the listed sites.
    The vertex atom is identified by _geom_angle.atom_site_label_2
    and accompanying symmetry operation code.

Type: Real

Units: degrees

Evaluation method:

    With a as geom_angle
    xc = List()
    bundle = [[a.site_symmetry_1,a.atom_site_label_1],
              [a.site_symmetry_2,a.atom_site_label_2],
              [a.site_symmetry_3.a.atom_site_label_3]]
    for symop,label in bundle {
        xf   =   SymEquiv(symop,  _atom_site[label].fract_xyz)
        xc ++=  _atom_sites_Cartn_transform.matrix * xf
    }
      v1,v2  =  xc[0]-xc[1], xc[2]-xc[1]

     _geom_angle.value =  Acosd ( v1 * v2 / ( Norm (v1) * Norm (v2) ) )

Category:
geom_angle