Full dimensional (15D) quantum-dynamical simulation of the protonated water-dimer I: Hamiltonian setup and analysis of the ground vibrational state

Details Full dimensional (15D) quantum-dynamical simulation of the protonated water-dimer I: Hamiltonian setup and analysis of the ground vibrational state Full dimensional (15D) quantum-dynamical simulation of the protonated water-dimer I: Hamiltonian setup and analysis of the ground vibrational state

2007-07-06

arxiv.org/abs/0707.1001v1

J. Chem. Phys., 2007, 127, 184302-1 -- 184302-17

Physics

Chemical Physics

46 pages, 5 figures, submitted to J. Chem. Phys

Scientific paper

10.1063/1.2787588

Quantum-dynamical full-dimensional (15D) calculations are reported for the protonated water dimer (H5O2+) using the multiconfiguration time-dependent Hartree (MCTDH) method. The dynamics is described by curvilinear coordinates. The expression of the kinetic energy operator in this set of coordinates is given and its derivation, following the polyspherical method, is discussed. The PES employed is that of Huang et al. [JCP, 122, 044308, (2005)]. A scheme for the representation of the potential energy surface (PES) is discussed which is based on a high dimensional model representation scheme (cut-HDMR), but modified to take advantage of the mode-combination representation of the vibrational wavefunction used in MCTDH. The convergence of the PES expansion used is quantified and evidence is provided that it correctly reproduces the reference PES at least for the range of energies of interest. The reported zero point energy of the system is converged with respect to the MCTDH expansion and in excellent agreement (16.7 cm-1 below) with the diffusion Monte Carlo result on the PES of Huang et al. The highly fluxional nature of the cation is accounted for through use of curvilinear coordinates. The system is found to interconvert between equivalent minima through wagging and internal rotation motions already when in the ground vibrational-state, i.e., T=0. It is shown that a converged quantum-dynamical description of such a flexible, multi-minima system is possible.

Affiliated with

Also associated with

No associations

Rating

Full dimensional (15D) quantum-dynamical simulation of the protonated water-dimer I: Hamiltonian setup and analysis of the ground vibrational state does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Full dimensional (15D) quantum-dynamical simulation of the protonated water-dimer I: Hamiltonian setup and analysis of the ground vibrational state, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Full dimensional (15D) quantum-dynamical simulation of the protonated water-dimer I: Hamiltonian setup and analysis of the ground vibrational state will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-90734