The truncated PNOs are then canonicalized to form a diagonal virtual Fock matrix to yield PNO orbital energies for the pair ij. For singles amplitudes t a i , the virtual space is assigned from PNOs of the diagonal pair ii, using a tighter occupation number tolerance (T CUT PNO × T DIAG SCALE , with T DIAG SCALE defaulting to 0.03). In the case of triples for DLPNO-CCSD(T)/T, the triplet density 53 is formed as the average of pair densities ij, jk, and ik. D ij , D jk , and D ik are formed from converged LCCSD doubles amplitudes (converged LMP2, LCEPA0, or LCCD amplitudes for weak pairs).