C. Leforestier - Academia.edu (original) (raw)
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Papers by C. Leforestier
Molecular Physics, 2007
Precise measurement of all tunneling splittings in the ground vibrational state of the water dime... more Precise measurement of all tunneling splittings in the ground vibrational state of the water dimer is essential for a complete and rigorous determination of the intermolecular potential energy surface. Here, accurate experimentally determined rotational constants and tunneling splittings were combined with estimates of the ground state acceptor switching (AS) splittings for both (H2O)2 and (D2O)2 in order to exactly predict
The Journal of Chemical Physics, 2002
Two polarizable six-dimensional water dimer intermolecular potential surfaces have been determine... more Two polarizable six-dimensional water dimer intermolecular potential surfaces have been determined by fitting the distributed multipole ASP ͑anisotropic site potential͒ potential form to microwave, terahertz, and midinfrared cavity ringdown (D 2 O) 2 spectra via a rigorous calculation of the water dimer eigenstates with the PSSH ͑pseudo-spectral split Hamiltonian͒ method. The fitted potentials accurately reproduce most ground-state vibration-rotation-tunneling spectra and yield excellent second virial coefficients for both H 2 O and D 2 O. The calculated dimer structure and dipole moment are close to those determined from microwave spectroscopy and high level ab initio calculations, except that the O-O distance ͑2.952 Å͒ is significantly shorter than the currently accepted experimental value. The dimer binding energy ͑4.85 kcal/mol͒ is considerably smaller than the accepted experimental result, but in excellent agreement with recent theoretical results, as are the acceptor switching and donor-acceptor interchange tunneling barriers and the cyclic water trimer and tetramer structures and binding energies.
Journal of Computational Physics, 1991
A comparison of three widely used time propagation algorithms for the time dependent Schrodinger ... more A comparison of three widely used time propagation algorithms for the time dependent Schrodinger equation is described. A typical evolution problem is chosen to demonstrate the efficiency and accuracy of the various methods on a numerical grid using a pseudo-spectral (FFT) spatial representation for scattering and bound state evolution. The methods used -second-order differencing, split operator propagation, Chebyshev polynomial expansion-are discussed in terms of their applicability to various classes of dynamic problems. A new method is introduced which is based upon a low-order Lancros technique. This method appears to offer an accurate and flexible alternative to the existing techniques. Overall the Chebyshev method is recommended for time independent potentials and the Lanczos method for time dependent potentials. :(' 59 oml-9991/91 83.00 LEFORESTIER ET AL.
Molecular Physics, 2007
Precise measurement of all tunneling splittings in the ground vibrational state of the water dime... more Precise measurement of all tunneling splittings in the ground vibrational state of the water dimer is essential for a complete and rigorous determination of the intermolecular potential energy surface. Here, accurate experimentally determined rotational constants and tunneling splittings were combined with estimates of the ground state acceptor switching (AS) splittings for both (H2O)2 and (D2O)2 in order to exactly predict
The Journal of Chemical Physics, 2002
Two polarizable six-dimensional water dimer intermolecular potential surfaces have been determine... more Two polarizable six-dimensional water dimer intermolecular potential surfaces have been determined by fitting the distributed multipole ASP ͑anisotropic site potential͒ potential form to microwave, terahertz, and midinfrared cavity ringdown (D 2 O) 2 spectra via a rigorous calculation of the water dimer eigenstates with the PSSH ͑pseudo-spectral split Hamiltonian͒ method. The fitted potentials accurately reproduce most ground-state vibration-rotation-tunneling spectra and yield excellent second virial coefficients for both H 2 O and D 2 O. The calculated dimer structure and dipole moment are close to those determined from microwave spectroscopy and high level ab initio calculations, except that the O-O distance ͑2.952 Å͒ is significantly shorter than the currently accepted experimental value. The dimer binding energy ͑4.85 kcal/mol͒ is considerably smaller than the accepted experimental result, but in excellent agreement with recent theoretical results, as are the acceptor switching and donor-acceptor interchange tunneling barriers and the cyclic water trimer and tetramer structures and binding energies.
Journal of Computational Physics, 1991
A comparison of three widely used time propagation algorithms for the time dependent Schrodinger ... more A comparison of three widely used time propagation algorithms for the time dependent Schrodinger equation is described. A typical evolution problem is chosen to demonstrate the efficiency and accuracy of the various methods on a numerical grid using a pseudo-spectral (FFT) spatial representation for scattering and bound state evolution. The methods used -second-order differencing, split operator propagation, Chebyshev polynomial expansion-are discussed in terms of their applicability to various classes of dynamic problems. A new method is introduced which is based upon a low-order Lancros technique. This method appears to offer an accurate and flexible alternative to the existing techniques. Overall the Chebyshev method is recommended for time independent potentials and the Lanczos method for time dependent potentials. :(' 59 oml-9991/91 83.00 LEFORESTIER ET AL.