We introduce new graph representation of bulk structures based on directions determined by relative positions. To detect neighboring atoms (j th neighboring atom, cij) of i th center atom (ci), we first transformed cartesian coordinates of all atoms into spherical coordinates centered at ci. Thus, all neighboring atoms (cij) are expressed in terms of one distance and two angle components, i.e., (ri,j, λi,j, φi,j), each component corresponding to radius, azimuth and elevation, respectively (Figure ). Then, a volume of the sphere centered at cij is divided into several sections by an arbitrary angle θ, which determines the number of sections, S. For example, θ = 90° divided the volume into 8 sections (Figure ). Note that smaller θ resulted in more finely divided sections (Figure ), where its effect on model accuracy, input crystal graph shape and similarity will be discussed below. Each section contains numerous neighboring atoms, where only the first nearest neighboring (FNN) atom is used to represent the neighboring environments.