import numpy as np
[docs]def numb_atoms () :
return 4
[docs]def gen_box () :
return np.eye(3)
[docs]def poscar_unit (latt) :
box = gen_box()
ret = ""
ret += "FCC : a = %f \n" % latt
ret += "%.16f\n" % (latt)
ret += "%.16f %.16f %.16f\n" % (box[0][0], box[0][1], box[0][2])
ret += "%.16f %.16f %.16f\n" % (box[1][0], box[1][1], box[1][2])
ret += "%.16f %.16f %.16f\n" % (box[2][0], box[2][1], box[2][2])
ret += "Type\n"
ret += "%d\n" % numb_atoms()
ret += "Direct\n"
ret += "%.16f %.16f %.16f\n" % (0.0, 0.0, 0.0)
ret += "%.16f %.16f %.16f\n" % (0.5, 0.5, 0.0)
ret += "%.16f %.16f %.16f\n" % (0.5, 0.0, 0.5)
ret += "%.16f %.16f %.16f\n" % (0.0, 0.5, 0.5)
return ret