TY - JOUR
T1 - Efficient Computation of Two-Electron Reduced Density Matrices via Selected Configuration Interaction
AU - Coe, Jeremy P.
AU - Moreno Carrascosa, Andrés
AU - Simmermacher, Mats
AU - Kirrander, Adam
AU - Paterson, Martin J.
N1 - Funding Information:
Funding from the Engineering and Physical Sciences Research Council UK (EPSRC) is gratefully acknowledged: EP/V006819 (A.K. and A.M.C.), EP/V049240 (A.K. and M.S.), EP/V006746 (M.J.P. and J.P.C.), EP/P001459 (M.J.P.), and EP/T021675 (M.J.P.). M.J.P. and A.K. also acknowledge support from the Leverhulme Trust (RPG-2020-208). Finally, A.K. acknowledges a Fellowship at the Swedish Collegium for Advanced Studies supported by the Erling-Persson Family Foundation and the Knut and Alice Wallenberg Foundation, as well as support by the Department of Energy, Office of Science, Basic Energy Sciences, under award number DE-SC0020276.
Publisher Copyright:
© 2022 American Chemical Society.
PY - 2022/11/8
Y1 - 2022/11/8
N2 - We create an approach to efficiently calculate two-electron reduced density matrices (2-RDMs) using selected configuration interaction wavefunctions. This is demonstrated using the specific example of Monte Carlo configuration interaction (MCCI). The computation of the 2-RDMs is accelerated by using ideas from fast implementations of full configuration interaction (FCI) and recent advances in implementing the Slater-Condon rules using hardware bitwise operations. This method enables a comparison of MCCI and truncated CI 2-RDMs with FCI values for a range of molecules, which includes stretched bonds and excited states. The accuracy in energies, wavefunctions, and 2-RDMs is seen to exhibit a similar behavior. We find that MCCI can reach sufficient accuracy of the 2-RDM using significantly fewer configurations than truncated CI, particularly for systems with strong multireference character.
AB - We create an approach to efficiently calculate two-electron reduced density matrices (2-RDMs) using selected configuration interaction wavefunctions. This is demonstrated using the specific example of Monte Carlo configuration interaction (MCCI). The computation of the 2-RDMs is accelerated by using ideas from fast implementations of full configuration interaction (FCI) and recent advances in implementing the Slater-Condon rules using hardware bitwise operations. This method enables a comparison of MCCI and truncated CI 2-RDMs with FCI values for a range of molecules, which includes stretched bonds and excited states. The accuracy in energies, wavefunctions, and 2-RDMs is seen to exhibit a similar behavior. We find that MCCI can reach sufficient accuracy of the 2-RDM using significantly fewer configurations than truncated CI, particularly for systems with strong multireference character.
UR - http://www.scopus.com/inward/record.url?scp=85139564883&partnerID=8YFLogxK
U2 - 10.1021/acs.jctc.2c00738
DO - 10.1021/acs.jctc.2c00738
M3 - Article
C2 - 36198067
SN - 1549-9618
VL - 18
SP - 6690
EP - 6699
JO - Journal of Chemical Theory and Computation
JF - Journal of Chemical Theory and Computation
IS - 11
ER -