Benchmark calculations of bound states of HO2 via basic Lanczos algorithm

We report benchmark calculations of all the bound state energies of HO2 on the DMBE IV potential of Varandas and coworkers using the basic Lanczos algorithm with no reorthogonalization. The results are in excellent agreement with previous calculations obtained using different methods. This work demonstrates the accuracy and efficiency of the basic Lanczos algorithm for a problem with a dimension of approximate to 10(6). Several aspects of convergence behavior of the algorithm are discussed. (C) 1997 Elsevier Science B.V.