Provided is a silicon-based molten composition including silicon, carbon, and a metal in which a solubility parameter (Csisol) defined by Equation (1) below is less than −0.37, wherein a SiC single crystal is formed by a solution method: Csisol=A−B+μ1−μ2  Equation (1) in Equation (1) above, A is a first energy (A) of a first evaluation lattice including silicon atoms, a carbon atom, and metal atoms in a silicon crystal lattice including metals and carbons, B is a second energy (B) of a second evaluation lattice including silicon atoms and metal atoms in a silicon crystal lattice including metals, μ1 is a constant of −5.422, and μ2 is a constant of −9.097.