import numpy as np
[docs]
def numb_atoms():
return 2
[docs]
def gen_box():
box = np.array(
[[1, 0, 0], [0.5, 0.5 * np.sqrt(3), 0], [0, 0, 2.0 * np.sqrt(2.0 / 3.0)]]
)
return box
[docs]
def poscar_unit(latt):
box = gen_box()
ret = ""
ret += "HCP : a = %f / sqrt(2)\n" % latt
ret += "%.16f\n" % (latt / np.sqrt(2))
ret += f"{box[0][0]:.16f} {box[0][1]:.16f} {box[0][2]:.16f}\n"
ret += f"{box[1][0]:.16f} {box[1][1]:.16f} {box[1][2]:.16f}\n"
ret += f"{box[2][0]:.16f} {box[2][1]:.16f} {box[2][2]:.16f}\n"
ret += "X\n"
ret += "%d\n" % numb_atoms()
ret += "Direct\n"
ret += f"{0:.16f} {0:.16f} {0:.16f}\n"
ret += f"{1.0 / 3:.16f} {1.0 / 3:.16f} {1.0 / 2:.16f}\n"
return ret