ct9b01165_si_001.pdf (2.68 MB)
Efficient Treatment of Large Active Spaces through Multi-GPU Parallel Implementation of Direct Configuration Interaction
journal contribution
posted on 2020-02-14, 15:13 authored by B. Scott Fales, Todd J. MartínezWe
have extended our graphical processing unit (GPU)-accelerated
direct configuration interaction program to multiple devices, reducing
iteration times for configuration spaces of 165 million determinants
to only 3 s using NVIDIA P100 GPUs. Similar improvements in the one-
and two-particle reduced density matrix formation allow for fast analytical
energy gradients and electronic properties. Our parallel algorithm
enables the calculation of
arbitrarily large configuration spaces (limited only by available
system memory), with iteration times of 13 min for an active space
of 18 electrons in 18 orbitals (2.4 billion determinants) using six
consumer grade NVIDIA 1080Ti GPUs. These advances enable routine molecular
dynamics simulations, geometry optimizations, and absorption spectrum
calculations for molecules with large configuration spaces, a task
that has heretofore required massive computational effort. In this
work, we demonstrate the utility of our program by generating the
absorption spectrum for diphenyl acetylene at the floating occupation
molecular orbital complete active space configuration interaction
level of theory. Several active spaces were investigated to assess
the dependence of spectral features on orbital space dimension.