Coupled-cluster theories can be used to compute electronic correlation energies of real materials with systematically improvable accuracy. However, the widely used coupled cluster singles and doubles plus perturbative triples [CCSD(T)] method is only applicable to insulating materials. For zero-gap materials the truncation of the underlying many-body perturbation expansion leads to diverging correlation energies, also known as infrared catastrophe. We present a novel perturbative triples formalism denoted as (cT) that yields convergent correlation energies in metallic systems [1]. Furthermore, we show that this approach resolves previously reported discrepancies for interaction energies of large molecules between CCSD(T) and quantum Monte Carlo calculations [2]. [1] N. Masios, A. Irmler, T. Schäfer and A. Grüneis. “Averting the Infrared Catastrophe in the Gold Standard of Quantum Chemistry”. Physical Review Letters 131 (2023), 186401. DOI: 10.1103/PhysRevLett.131.186401. [2] T. Schäfer, A. Irmler, A. Gallo and A. Grüneis. “Understanding Discrepancies of Wavefunction Theories for Large Molecules”. arxiv:2407.01442 (2024). DOI: 10.48550/arXiv.2407.01442.