Uncategorized

Development and Benchmarking of Open Force Field v1.0.0, the Parsley Small Molecule Force Field

Abstract We present a methodology for defining and optimizing a general force field for classical molecular simulations, and we describe its use to derive the Open Force Field 1.0.0 small molecule force field, code-named Parsley. Rather than traditional atom-typing, our approach builds on the SMIRKS-native Open Force Field (SMIRNOFF) parameter assignment formalism, which handles increases…

Uncategorized

Communication: Multi-reference Approach to the Computation of Double-Core-Hole Spectra

Abstract Double-Core Hole (DCH) states of small molecules are assessed with the restricted<br />active space self-consistent field (RASSCF) and multi-state restricted active space perturbation<br />theory of second order (MS-RASPT2) approximations. To ensure an unbiased<br />description of the relaxation and correlation effects on the DCH states, the neutral<br />ground state and DCH wave functions are optimized…

Uncategorized

A close-up look at the chemical space of commercially available building blocks for medicinal chemistry

The ability to efficiently synthesize desired compounds can be a limiting factor for chemical space exploration in drug discovery. This ability is conditioned not only by the existence of well-studied synthetic protocols but also by the availability of corresponding reagents, so-called building blocks (BB). In this work, we present a detailed analysis of the chemical…

Uncategorized

Origin of The Failure of Density Functional Theories in Predicting Inverted Singlet-Triplet Gaps

Recent experimental and theoretical studies have shown several new organic molecules that violate Hund’s rule and have the first singlet excited state lower in energy than the first triplet excited state. While many correlated single reference wave function methods have successfully predicted excited state energetics of these low-lying states, linear-response time-dependent density functional theory (LR-TDDFT)…

Uncategorized

Is the quantum Internet finally here?

If you’ve ever attended the premiere of a film or an event where a new type of car is presented, you’ll know that there’s a slight buzz of excitement that comes from not knowing what to expect. I’ve been feeling that buzz for the past two weeks, leading up to an event that promised a…