Frac2cart.m

Converts fractional crystallographic coordinates to Cartesian coordinates. Syntax:

     [XYZ,va,vb,vc]=frac2cart(a,b,c,alpha,beta,gamma,ABC)

Parameters:

   a,b,c            - three unit cell dimensions

   alp,bet,gam      - three unit cell angles, degrees

   ABC              - fractional atomic coordinates as
                      Nx3 array of numbers

Outputs:

   XYZ              - Cartesian atomic coordinates as
                      Nx3 array of numbers

   va, vb, vc       - primitive lattice vectors