crystal.py 文件源码

def pbc_parameters(self):
        """
        Calculates constants used in periodic boundary conditions.
        """
        uc_cos = [math.cos(math.radians(a)) for a in self.uc_angle]
        uc_sin = [math.sin(math.radians(a)) for a in self.uc_angle]
        a, b, c = self.uc_size
        v = self.frac_ucv

        xf1 = 1 / a
        xf2 = - uc_cos[2] / (a * uc_sin[2])
        xf3 = (uc_cos[0] * uc_cos[2] - uc_cos[1]) / (a * v * uc_sin[2])
        yf1 = 1 / (b * uc_sin[2])
        yf2 = (uc_cos[1] * uc_cos[2] - uc_cos[0]) / (b * v * uc_sin[2])
        zf1 = uc_sin[2] / (c * v)
        self.to_frac = [xf1, xf2, xf3, yf1, yf2, zf1]

        xc1 = a
        xc2 = b * uc_cos[2]
        xc3 = c * uc_cos[1]
        yc1 = b * uc_sin[2]
        yc2 = c * (uc_cos[0] - uc_cos[1] * uc_cos[2]) / uc_sin[2]
        zc1 = c * v / uc_sin[2]
        self.to_car = [xc1, xc2, xc3, yc1, yc2, zc1]