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 Tools annual

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 monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

Over the past few years pair coupled cluster doubles (pCCD) has shown promisefor the description of strong correlation. This promise is related to itsapparent ability to match results from doubly occupied configurationinteraction (DOCI), even though the latter method has exponential computationalcost. Here, by modifying the full configuration interaction quantum Monte Carlo(FCIQMC) algorithm to sample only the seniority zero sector of Hilbert space,we show that the DOCI and pCCD energies are in agreement for a variety of 2DHubbard models, including for systems well out of reach for conventionalconfiguration interaction algorithms. Our calculations are aided by the signproblem being much reduced in the seniority zero space compared with the fullspace. We present evidence for this, and then discuss the sign problem in termsof the wave function of the system which appears to have a simplified signstructure.

journal of chemical physics online/the journal of chemical physics/journal of chemical physics

Using full configuration interaction quantum Monte Carlo in a seniority  zero space to investigate the correlation energy equivalence of pair coupled  cluster doubles and doubly occupied configuration interaction