QUANTUM MONTE-CARLO DETERMINATION OF THE LITHIUM 2(2)S-]2(2)P OSCILLATOR STRENGTH - HIGHER PRECISION

We employ a quantum Monte Carlo method for the oscillator strength to the computation of the controversial 2 2S→2 2P transition of the Li atom. We use simple trial functions that are optimized for accuracy in coordinate expectation values as well as the energy. We obtain an oscillator strength of 0.7431(6), in very good agreement with the experimental value of 0.7416(12) [A. Gaupp, P. Kuske, and H. J. Andrä, Phys. Rev. A 26, 3351 (1982)]. The precision obtained here, an order of magnitude greater than that of our previous value [R. N. Barnett, P. J. Reynolds, and W. A. Lester, Jr., Int. J. Quantum Chem. 42, 837 (1992)] shows that the quantum Monte Carlo oscillator strength unambiguously supports the experimental value over recent theoretical values. © 1995 The American Physical Society.