The absorption of stopped negative pions by 6Li, accompanied by the emission of two nucleons, is studied in terms of the direct pion absorption by nucleon pairs. The absorption rates of pions are expressed as a function of the centre-of-mass and relative momenta of the nucleon pairs for investigating the momentum distributions of nucleons in the nucleus. The calculated results are compared with experimental data. The data are explained by single-particle harmonic-oscillator functions if the short-range correlation of nucleon pairs is taken into account in the calculation.