[24a-E203-1~10] 23.1 Joint Session N "Informatics"

▲ [24a-E203-1] Ab initio binding energy calculations for molecules in the G2 set: Towards chemical accuracy by the Jastrow correlated Antisymmetrized Geminal Power (JAGP)

〇(DC)Abhishek Raghav¹, Ryo Maezono¹, Kenta Hongo¹, Sandro Sorella², Kousuke Nakano^1,2 (1.JAIST, 2.SISSA)

Keywords:Quantum Monte Carlo, G2 set, Binding energy

We report accurate all-electron ab initio binding energy calculations for 55 molecules in the G2 set, using lattice regularized diffusion Monte Carlo (LRDMC) within TurboRVB QMC package. We employ both the more traditional Ansatz namely the Jastrow Slater Determinant as well as the more flexible Ansatz namely the Jastrow antisymmetrized geminal power with singlet correlation (JAGPs). The many-body wave functions are first optimized at the variational Monte Carlo (VMC) level, which is followed by the LRDMC projection. Remarkably, for many molecules the LRDMC binding energies obtained using the JAGPs Ansatz reach the chemical accuracy (~1 kcal/mol) and for most of the other cases the binding energies are accurate within ~5 kcal/mol. We further expect to improve upon the JAGPs binding energies by using the Pfaffian Ansatz. This work shows the effectiveness of these more flexible Ansatz for binding energy calculations and electronic structure simulations in general.