BEGIN:VCALENDAR
VERSION:2.0
PRODID:-//Talks.cam//talks.cam.ac.uk//
X-WR-CALNAME:Talks.cam
BEGIN:VEVENT
SUMMARY:Scalable multi-reference chemistry using quantum Monte Carlo - Dr 
 Nick Blunt\, Riverlane
DTSTART:20211124T143000Z
DTEND:20211124T153000Z
UID:TALK160933@talks.cam.ac.uk
CONTACT:Lisa Masters
DESCRIPTION:In quantum chemistry we have many scalable methods for the acc
 urate treatment of single-reference problems\, notably including density f
 unctional theory and coupled cluster theory. However\, these methods are l
 ess reliable when applied to strongly multi-reference problems. In such ca
 ses\, a common approach is to perform a complete active space (CAS) proced
 ure followed by perturbation theory. However\, solving this CAS problem is
  challenging beyond small active spaces. In this talk\, we will investigat
 e variational Monte Carlo (VMC) and the fixed-node approximation as an app
 roach for solving the active space problem. Specifically\, we will use VMC
  to optimise Jastrow mean-field wave functions\, which can provide an effi
 cient representation of multi-reference states. We then investigate full c
 onfiguration interaction quantum Monte Carlo (FCIQMC) as a method to impro
 ve the accuracy of these VMC solutions further\, and investigate the scali
 ng of this approach.\n
LOCATION:Zoom and Dept of Chemistry\, Wolfson Lecture Theatre
END:VEVENT
END:VCALENDAR