Assessing the utility of phase-space-localized basis functions: Exploiting direct product structure and a new basis function selection procedure.In this paper we show that it is possible to use an iterative eigensolver in conjunction with Halverson and Poirier's symmetrized Gaussian (SG) basis [T. Halverson and B. Poirier, J. Chem. Phys. 137, 224101 (2012)] to compute accurate vibrational energy levels of molecules with as many as five atoms.  The SG basis we work with is orders of magnitude smaller than the basis made by using a classical energy criterion.  We find significant convergence errors in previous calculations with SG bases.  For sum-of-product Hamiltonians, SG bases large enough to compute accurate levels are orders of magnitude larger than even simple pruned bases composed of products of harmonic oscillator functions.
SG
Assessing the utility of phase-space-localized basis functions: Exploiting direct product structure and a new basis function selection procedure.In this paper we show that it is possible to use an iterative eigensolver in conjunction with Halverson and Poirier's symmetrized Gaussian (SG) basis [T. Halverson and B. Poirier, J. Chem. Phys. 137, 224101 (2012)] to compute accurate vibrational energy levels of molecules with as many as five atoms.  The SG basis we work with is orders of magnitude smaller than the basis made by using a classical energy criterion.  We find significant convergence errors in previous calculations with SG bases.  For sum-of-product Hamiltonians, SG bases large enough to compute accurate levels are orders of magnitude larger than even simple pruned bases composed of products of harmonic oscillator functions.
SG
Assessing the utility of phase-space-localized basis functions: Exploiting direct product structure and a new basis function selection procedure.In this paper we show that it is possible to use an iterative eigensolver in conjunction with Halverson and Poirier's symmetrized Gaussian (SG) basis [T. Halverson and B. Poirier, J. Chem. Phys. 137, 224101 (2012)] to compute accurate vibrational energy levels of molecules with as many as five atoms.  The SG basis we work with is orders of magnitude smaller than the basis made by using a classical energy criterion.  We find significant convergence errors in previous calculations with SG bases.  For sum-of-product Hamiltonians, SG bases large enough to compute accurate levels are orders of magnitude larger than even simple pruned bases composed of products of harmonic oscillator functions.
SG