English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We present a new approach to calculate excited states with the fullconfiguration interaction quantum Monte Carlo (FCIQMC) method. The approachuses a Gram-Schmidt procedure, instantaneously applied to the stochasticallyevolving distributions of walkers, to orthogonalize higher energy statesagainst lower energy ones. It can thus be used to study several of thelowest-energy states of a system within the same symmetry. This additional stepis particularly simple and computationally inexpensive, requiring only a smallchange to the underlying FCIQMC algorithm. No trial wave functions orpartitioning of the space is needed. The approach should allow excited statesto be studied for systems similar to those accessible to the ground-statemethod, due to a comparable computational cost. As a first application weconsider the carbon dimer in basis sets up to quadruple-zeta quality, andcompare to existing results where available.

An excited-state approach within full configuration interaction quantum Monte Carlo