Time-dependent optimized coupled-cluster method for multielectron dynamics

TL;DR

This paper introduces a novel time-dependent coupled-cluster method with optimized orbitals for simulating multielectron dynamics under intense laser fields, offering a size-extensive and gauge-invariant alternative to existing methods.

Contribution

The paper formulates and implements the TD-OCC method with double and triple excitations, providing a new efficient approach for multielectron dynamics in intense laser fields.

Findings

Successfully derived equations of motion for the method.

Implemented TD-OCC with double and triple excitations.

Applied the method to Ar atom under intense laser field.

Abstract

Time-dependent coupled-cluster method with time-varying orbital functions, called time-dependent optimized coupled- cluster (TD-OCC) method, is formulated for multielectron dynamics in an intense laser field. We have successfully derived equations of motion for CC amplitudes and orthonormal orbital functions based on the real action functional, and implemented the method including double excitations (TD-OCCD) and double and triple excitations (TD-OCCDT) within the optimized active orbitals. The present method is size extensive and gauge invariant, a polynomial cost-scaling alternative to the time-dependent multiconfiguration self-consistent-field method. The first application of the TD-OCC method to intense-laser driven correlated electron dynamics in Ar atom is reported.