No abstract

In this paper, we compare and contrast basis set sampling techniques recently developed for use in the ab initio multiple cloning method, a direct dynamics extension to the multiconfigurational Ehrenfest approach, used recently for the quantum simulation of ultrafast photochemistry. We demonstrate that simultaneous use of basis set cloning and basis function trains can produce results which are converged to the exact quantum result. To demonstrate this, we employ these sampling methods in simulations of quantum dynamics in the spin boson model with a broad range of parameters and compare the results to accurate benchmarks.

In this paper we present a portable magnetocardiography device. The focus of this development was delivering a rapid assessment of chest pain in an emergency department. The aim was therefore to produce an inexpensive device that could be rapidly deployed in a noisy unshielded ward environment. We found that induction coil magnetometers with a coil design optimized for magnetic field mapping possess sufficient sensitivity (104f T / √ Hz noise floor at 10Hz) and response (813f T /µV at 10Hz) for cycle averaged magnetocardiography and are able to measure depolarisation signals in an unshielded environment. We were unable to observe repolarisation signals to a reasonable fidelity. We present the design of the induction coil sensor array and signal processing routine along with data demonstrating performance in a hospital environment.

In this paper we report a version of the Coupled Coherent States (CCS) method which is able to accurately compute the HHG spectrum of an electron in a laser field in one dimension by the use of trajectory-guided grids of Gaussian wavepackets. It is shown that by periodic re-projection of the wavefunction and dynamically altering the basis set size, the method can account for a wavefunction which spreads out to cover a large area in phase space while still keeping computational expense low. The HHG spectra obtained show good agreement with those from a time dependent Schrödinger equation solver. We show also that the part of the wavefunction which is responsible for HHG moves along a periodic orbit which is far from that of classical motion. Although this paper is a proof of principle and therefore focussed on a simple one-dimensional system, future generalisations for the multi-electron case are discussed.

Fully quantum nonadiabatic dynamics calculation of 2-ethylpyrrole photodissociation shows the experimentally obtained ultrafast time-constant has two components.