sinematrix.py 文件源码

def sine_matrix(self, system):
        """Creates the Sine matrix for the given system.
        """
        # Cell and inverse cell
        B = system.get_cell()
        B_inv = system.get_cell_inverse()

        # Difference vectors in tensor 3D-tensor-form
        diff_tensor = system.get_displacement_tensor()

        # Calculate phi
        arg_to_sin = np.pi * np.dot(diff_tensor, B_inv)
        phi = np.linalg.norm(np.dot(np.sin(arg_to_sin)**2, B), axis=2)

        with np.errstate(divide='ignore'):
            phi = np.reciprocal(phi)

        # Calculate Z_i*Z_j
        q = system.get_initial_charges()
        qiqj = q[None, :]*q[:, None]
        np.fill_diagonal(phi, 0)

        # Multiply by charges
        smat = qiqj*phi

        # Set diagonal
        np.fill_diagonal(smat, 0.5 * q ** 2.4)

        return smat