Electronic band structure and inter-atomic bonding in layered 1111-like Th-based pnictide oxides ThCuPO, ThCuAsO, ThAgPO, and ThAgAsO from first principles calculations

► 1111 Th-based pnictide oxides ThMPnO behave as semimetals. ► ThMPnO are “intermediate” between superconducting and semiconducting 1111 phases. ► The Th 5f states in these materials are itinerant and partially occupied. ► The bonding in ThMPnO is a high-anisotropic mixture of ionic and covalent contributions.