PNNL

Abstract

There is a pressing need for accurate calculation of finite temperature ground and excited state properties of nanoscale systems relevant to structural biology, hydrogen economy, environmental and material science problems. To address this challenging task we have designed a multiscale dynamical approach that combines the accuracy and computational complexity of coupled-cluster (CC) methods with the efficiency of classical molecular dynamics simulations. Our methodology is based on a seamless integration between the generic QM/MM interface, Tensor Contraction Engine module, and the classical molecular dynamics module of NWChem and offers an unprecedented ability for accurate large scale calculations of thermodynamics of ground and excited state properties. We illustrate our approach by large scale dynamical simulation of excited state spectrum of the cytosine base in its native DNA environment using variant of the completely renormalized equation-of-motion method with singles, doubles, and non-iterative triples (CR-EOMCCSD(T)).