The present invention provides carbon-based clathrate compounds, including a carbon-based clathrate compound that includes a clathrate lattice with atoms of at least one element selected from the group consisting of carbon and boron as a host cage structure; guest atoms encapsulated within the clathrate lattice; and, substitution atoms that may be substituted for at least one portion of the carbon and boron atoms that constitute the clathrate lattice. In one embodiment, the invention provides a carbon-based clathrate compound of the formula LaB3C3.